Certain ethers of certain di and trihalo-1-hydroxy-2-(fluoroalkyl)1H-imidazo(4,5-b)pyridine derivatives

ABSTRACT

Ethers of di and trihalo-1-hydroxy-2-(1,1-difluoroalkyl)-1H-imidazo(4,5-b)pyridine compounds, useful as herbicides and rodenticides.

CROSS-REFERENCE TO RELATED APPLICATION

This is a continuation of my copending application Ser. No. 613,387, filed Sept. 15, 1975 and now abandoned. Application Ser. No. 613,387 was a continuation-in-part of my copending application Ser. No. 479,006, filed June 13, 1974, and abandoned after the filing of application Ser. No. 613,387. Application Ser. No. 479,006 was in turn a continuation-in-part of my then copending application Ser No. 236,195, filed Mar. 20, 1972 and issued June 18, 1974 as 3,818,022. Application Ser. No. 236,195 was, in turn, a continuation-in-part of my then copending application Ser. No. 181,6338, filed Sept, 17, 1971, and abandoned after the filing of application Ser. No. 236,195. Application Ser. No. 181,638 was, in turn, a continuation-in-part of my then copending application Ser. No. 100,410, filed Dec. 21, 1970, and abandoned after the filing of application Ser. No. 181,638.

SUMMARY OF THE INVENTION

The present invention is directed to ethers and esters of 1-hydroxy-2-(1,1-difluoroalkyl)-1H-imidazo(4,5-b)pyridine compounds. These derivatives are of the following formula: ##STR1## In the above and succeeding formulae throughout the present specification and claims, R¹ represents hydrogen, chlorine, fluorine, difluoromethyl, perfluoroalkyl of C₁ -C₆, or radical of the formula ##STR2## wherein each Z independently represents hydrogen or halogen and m represents 0 or 1; R² represents amino, halogen, nitro, cyano, loweralkyl of C₁ -C₄, perfluoroalkyl of C₁ -C₈, --CF₂ Cl, --CF₂ H, or loweralkylsulfonyl of C₁ -C₄, subject to the limitations (1) that all R² substituents together contain not more than 8 carbon atoms; (2) that not more than two R² symbols represent loweralkylsulfonyl groups; and (3) that where two loweralkylsulfonyl groups are present, they are located at the 5- and 7-positions; n represents an integer of from 1 to 3 both inclusive; and R³ represents

1. alkyl of C₁ -C₈ ;

2 alkenyl of C₂ -C₈ ;

3 cycloalkyl of C₅ -C₅ ;

4. benzyl;

5. phenethyl;

6. alkanoyl of C₂ -C₁₆ ;

7. alkenoyl of C₃ -C₁₆ ;

8. carbamoyl of the formula ##STR3## wherein X represents oxygen or sulfur; and one R⁴ represents phenyl, loweralkyl of C₁ -C₄, or loweralkenyl of C₂ -C₄, and the other R⁴ represents hydrogen, loweralkyl of C₁ -C₄, or loweralkenyl of C₂ -C₄, subject to the limitation that both R⁴ moieties taken together do not contain more than six carbon atoms, or both R⁴ moieties taken together represent straight-chain alkylene of C₂ -C₆, both inclusive;

9. radical of the formulae ##STR4## loweralkyl of C_(1`-C) ₄ or ##STR5## wherein X is, as above, oxygen or sulfur. 10. radical of the formula ##STR6## wherein R⁵ represents methylene, ethylene, or vinylene, and n represents 0 or 1;

11. radical of the formulae ##STR7## substituted phenyl and ##STR8## substituted phenyl, wherein substituted phenyl is a phenyl radical bearing from 1-3 substituents, each of which is independently amino, nitro, chloro, methyl, or methoxy, and R⁶ represents loweralkylene or C₁ -C₄, both inclusive;

2. --SO₂ --R⁷ wherein R⁷ is loweralkyl as above defined, cycloalkyl of C₅ -C₆, substituted phenyl as above defined, or benzyl;

13. tetrahydro-2-pyranyl.

The compounds so defined are useful as herbicides. In addition, they can be used as starting materials for a process which results in rearrangement or reduction depending on the reaction conditions employed.

Detailed Description of the Invention

In the present specification and claims, the term "halogen" is employed to designate bromine, chlorine, fluorine, and iodine, only. In the case of the loweralkyl, loweralkenyl, alkyl, alkenyl, alkanoyl, alkenoyl, and loweralkylene radicals, such radical can be branched or straight-chain.

An essential and distinguishing structural feature of the compounds of the present invention is the substituent at the 2-position (--CF₂ --R¹); representative such radicals include the following:

difluorometyl

trifluoromethyl

difluorochloromethyl

pentafluoroethyl

heptafluoro-n-propyl

1,1-difluoroethyl

1,1-difluoro-n-propyl 1,1-difluoro-2-bromoethyl

1,1-difluoro-2-chloroethyl

1,1-difluoro-2,3-dichloro-n-propyl

1,1-difluoro-3-bromo-n-propyl

1,1,2-trifluoroethyl

1,1,2-trifluoro-n-propyl

1,1,2,3-tetrafluoro-n-propyl

1,1-difluoro-2-bromo-3-chloro-n-propyl

perfluoro-n-butyl

perfluoro-n-pentyl

perfluoro-n-hexyl

1,1,2,2-tetrafluoroethyl

Preferred groups are trifluorometyl, difluorometyl, difluorochlorometyl, 1,1,2,2-tetrafluoroethyl, and pentafluoroethyl.

The compounds of the present invention are typically crystalline solids. They are prepared to standard procedures for the derivatization of hydroxy groups. Hence, those of the derivatives claimed herein which are ethers can be prepared by those procedures discussed in chapter 6 of Synthetic Organic Chemistry, by Wagner and Zook (John Wiley and Sons, Inc., New York, 1965). The same reference discusses various synthetic procedures which can be employed for the synthesis of those derivatives claimed herein which are carboxylic acid esters (chapter 14), carbamic acid esters (chapter 23), and sulfonic acid esters (chapter 37).

Generally, the compounds of the present invention are conveniently prepared by the reaction of the corresponding 1-hydroxy compounds: ##STR9## with a halide of the formula R³ --X, where X is halo, in the presence of an alkali metal carbonate or other hydrogen halide acceptor. An inert liquid reaction medium can be used. The reaction proceeds under a wide range of temperatures, but is preferably conducted at temperatures of from -20° C. to the reflux temperature. Separation, and if desired, purification, are carried out in conventional procedures.

While the foregoing is the most general method, other methods are convenient and may be preferred for some of the compounds. Thus, those carbamates of the formula ##STR10## are more readily prepared by reacting the corresponding 1-hydroxy-1H-imidazol(4,5-b)pyridine with an isocyanate of the formula

    O═N═C-loweralkyl or loweralkenyl

The reaction is conducted in conventional procedures.

Likewise, the carboxylic ester compounds of the present invention other than the carbamate esters are often preferably prepared by reacting the desired carboxylic acid as its anhydride with the corresponding 1-hydroxy-1H-imidazo(4,5-b) pyridine starting compound. Furthermore, in the case of the present compounds whichare ethers preparation is sometimes preferably carried out by reaction of the 1-hydroxy-1H-imidazo(4,5-b)pyridine with an olefin; this is particularly preferred in the case of the tetrahydro-2-pyranyl ether. The alkenyl ethers may also be preferably prepared by addition to an alkyne

Yet other synthetic techniques can be used in the preparation of the compounds of the present invention; examples are the use of N,N'-carbonyldiimidazole or N,N'-dicyclohexyldicarbodiimide (See Reagents for Organic Synthesis, Fieser and Fieser (John Wiley and Sons 1967), pages 114 et seq. and 231 et seq., respectively.

The following examples illustrate the present invention and wiil enable those skilled in the art to practice the same.

EXAMPLE 1: 1-METHOXY-6-CHLORO-2-(TRIFLUOROMETHYL)-1H-IMIDAZO-(4,5,-b) PYRIDINE

1-Hydroxy-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine (5 grams), 80 milliliters of acetone, 5 milliliters of methyl iodide, and 10 grams of anhydrous potasssium carbonate were mixed, heated and refluxed with stirring for twelve hours. The reaction mixture was then filtered, evaporated and eluted off of a silica column with diethyl ether, yielding the desired 1-methoxy-6-chloro-2-(trifluoromethyl-1H-imidazo(4,5-b)pyridine product. It was recrystallized from petroleum ether (boiling at 60°-80° C.). The product so obtained melted at 91-20° C.

Analysis, Calc.: C, 38.20; H, 1.99; N, 16.70. Found: C, 37.92; H, 2.32; N, 16.75.

EXAMPLE 2: 1-BENZYLOXY-6-CHLORO-2-(TRIFLUOROMETYL)-1H-IMIDAZO(4,5-b) PYRIDINE

1-Hydroxy-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b) pyridine (5 grams), 10 milliliters of benzyl bromide, 20 grams of anhydrous potassium carbonate, andd 100 milliliters of ethanol were mixed, heated to reflux, and refluxed for 1 hour. The reaction mixture was then filtered, evaporated under vacuum, and extracted with diethyl ether. The extract was filtered and evaporated under vacuum yielding a dark oil which on standing crystallized as the desired 1-benzyloxy-6-chloro-2-(trifluoromethyl)-1H-imadazo (4,5-b) pyridine. It was recrystallized from a mixture of acetone and petroleum ether boiling at 60°-80° C., m.p., 107°-09° C.

Analysis, Calc.: C, 51.31; H, 2.77; N, 12.82. Found: C, 51.54; H, 2.62; N, 13.12.

EXAMPLE 3: 1-ACETOXY-6-CHLORO-2-(TRIFLUOROMETHYL)-1H-IMIDAZO-(4,5-b) PYRIDINE

1-Hydroxy-6-chloro-2-(trifluorometyl)-1H-imidazo-(4,5,-b) pyridine (5 grams), 25 milliliters of acetic anhydride and 0.1 milliliter of sulfuric acid were mixed with stirring at 25° C. for 15 minutes. The reaction mixture was then heated to reflux and refluxed for 1/2 hour, poured into ice with stirring for ten minutes and filtered. Filtration yielded the desired 1-acetoxy-6-chloro--(trifluorometyl)-1H-imidazo(4,5-b) pyridine product as a solid. It was taken up in ether, dried over magnesium sulfate, and the ether evaporated. The product then melted at 103°-04° C.

Analysis, Calc.: C, 38.65; H, 1.80; N, 15.02. Found: C, 38.88; H, 1.92; N, 15.02.

EXAMPLE 4: 1-OCTANOYLOXY-6-CHLORO-2-(TRIFLUOROMETYL)-1H-IMIDAZO(4,5-b) PYRIDINE

To 1-hydroxy-5-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b) pyridine (2.37 grams) in 5 milliliters of pyridine was added octanoyl chloride (1.63 grams). The addition was carried out portionwise with stirring and resulted in the precipitation of a white solid. The reaction mixture was set on a steam bath for twenty minutes then poured over ice cold aqueous HCl. An oil separated and subsequently crystallized on vigorous stirring. This precipitate was removed by filtration, dissolved in ether, dried over magnesium sulfate, filtered, and ether removed by evaporation under vacuum. The substance was purified by distillation, m.p., 33.5°-35.5° C.

Analysis, Calc.: C, 49.52; H, 4.71; N, 11.55. Found: C, 49.81; H, 4.93; N, 11.29.

EXAMPLE 5: 1-(ALLYLCARBAMOYLOXY)-6-CHLORO-2-(TRIFLUOROMETHYL)-1H-IMIDAZO(4,5-b) PYRIDINE

1-Hydroxy-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b) pyridine (4.6 grams) was dissolved in 10 milliliters of diethyl ether and 2.4 milliliters of allyl isocyanate added and the reaction mixture stirred at room temperature for 36 hours. The reaction mixture was then filtered yielding 4.75 grams of a white powder, the desired 1-(allylcarbamoyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b) pyridine. An additional portion of the product was obtained by evaporating the filtrate. The combined products were recrystallized from a mixture of diethyl ether and petroleum ether boiling at 60°-80° C., m.p., about 210° C.

Analysis, Calc.: C, 41.20; H, 2.51; N, 17.47. Found: C, 41.42; H, 2.51; N, 17.25.

EXAMPLE 6 1(METHYLSULFONYLOXY)-6-CHLORO-2-(TRIFLUOROMETHYL)-1H-IMIDAZO(4,5-b)PYRIDINE

1-Hydroxy-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine (5 grams) in 15 milliliters of pyridine was cooled to 5° C. with stirring and methylsulfonyl chloride (5 milliliters) was added in 1-milliliter portions, maintaining the temperature at about 5° C. After the addition was completed, the reaction mixture was stirred for 2 hours at 5°-10° C., then poured into 30 grams of ice and 20 milliliters of concentrated hydrochloric acid. The desired 1-(methylsulfonyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine product precipitated and was separated by filtration and washed with water. The washed product was taken up in diethyl ether with a trace of acetone, dried over magnesium sulfate and the solvent evaporated under vacuum. The product so obtained melted at 136.7° C.

Analysis, Calc.: C, 30.44; H, 1.60; N, 13.31.

Found: C, 30.48; H, 1.83; N, 13.00.

EXAMPLE 7 1-METHOXY=6-AMINO-5,7-DIBROMO=2-(TRIFLUOROMETHYL)-1H-IMIDAZO(4,5-b)PYRIDINE

6-Amino-5,7-dibromo-2-trifluormethyl-1-jhydroxy-1H-imidazo(4,5-b)pyridine (1 gram) was mixed and stirred for 2 hours with 2 milliliters of methyl iodide, 2 grams of potassium carbonate, and 10 milliliters of acetone. The reaction mixture was then diluted with about 80 milliliters of ether and washed with five 15-milliliter portions of water. The ether layer was dried over magnesium sulfate and filtered with carbon, and the ether removed on a rotary evaporator. The resulting 1-methoxy-6-amino-5,7-dibromo-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine product melted at 169°-72° C. A portion was recrystallized from methanol, m.p., 17°-8° C.

Analysis, Calc.: C. 24.64; H, 1.29; N, 14.37.

Found: C, 24.96; H, 1.51; N, 14.48.

EXAMPLE 8: 1-(METHYLCARBAMOYLOXY)-6-CHLORO-5,7-DIBROMO-2-(TRIFLUOROMETHYL)-1H-IMIDAZO(4,5-b)PYRIDINE

6-Chloro-5,7-dibromo-1-hydroxy-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine (0.9 gram) was mixed with ether (15 milliliters) and methyl isocyanate (2 milliliters) and stirred for fifteen minutes. Triethylamine (0.01 milliliters) was added, and the solution became homogenous. It was permitted to stand for 16 hours, diluted with 50 milliliters diethyl ether; washed with 0.5NHC1, water, and saturated NaC1; then dried over magnesium sulfate, and evaporated. The resulting 1-(methylcarbamoyloxy)-6-chloro-5,7-dibromo-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine product was recrystallized from chloroform, m.p., 216° C.

Analysis, Calc.: C, 23.89; H, 0.89; N, 12.38.

Found C, 23.82; H, 0.90; N, 12.16.

EXAMPLES 9-61

Other representative compounds of the present invention, prepared in accordance with the foregoing teachings, include the following:

1-allyloxy-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine, n_(D) ²³.5 1.5204.

1-isopropoxy-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)-pyridine, m.p., 49°-51° C.

1-ethoxy-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine, n_(D) ²⁵ 1.5082.

1-(methylcarbamoyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine, m.p., 267° C.

1-(2-methoxy-3,6-dichlorobenzoyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine, m.p., 148°-9° C.

1-ethoxy-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)-pyridine, n_(D/25) 1.5100.

1-methoxy-6-nitro-2-(trifluoromethyl)-1H-imidazo(4,5-b)-pyridine.

1-n-octyloxy-6-(methylsulfonyl)-2-(heptafluoro-n-pyropyl)-1H-imidazo(4,5-b)pyridine.

1-n-butoxy-6-fluoro-2-(1,1difluoroethyl)-1H-imidazo(4,5-b)-pyridine.

1-phenethoxy-2,6-bis(chlorodifluoromethyl)-1H-imidazo(4,5-b)-pyridine.

1-vinyloxy-2,6-bis(difluoromethyl)-1H-imidazo(4,5-b)pyridine.

1(dimethylcarbamoyloxy)-6-bromo-2-(perfluoro-n-hexyl)-1H-imidazo(4,5-b)pyridine.

1-methacryloyloxy-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-lauroyloxy-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1(2,4-dichlorophenoxyacetoxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-benzoyloxy-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(phenylacetoxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine.

1-(3-phenylpropionyloxy)-6-(methylsulfonyl)-1H-imidazo-(4,5-b)pyridine.

1-cinnamoyloxy-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)-pyridine.

1-(3-(2,4,5-trichlorophenoxy)propionyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidzoe(4,5-b)pyridine.

1-cyclohexyloxy-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine.

1-(phenylsulfonyloxy)-2,6-bis(difluoromethyl)-1H-imidazo(4,5-b)-pyridine.

1-(benzylsulfonyloxy)-6-chloro-2-(difluoromethyl)-1H-imidazo-(4,5-b)pyridine.

1-(cyclohexylsulfonyloxy)-6-nitro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-((p-chlorophenyl)sulfonyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(2-butenyloxy)-6-(isopropylsulfonyl)-2-(1,1-difluoro-3-chloropropyl)-1H-imidazo(4,5-b)pyridine.

1-(6-octenyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine.

1-(9-hexadecenoyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine.

1-(isopropylthiocarbamoyloxy)-6-chloro-2-(pentafluoroethyl)-1H-imidazo(4,5-b)pyridine.

1-(3-amino-2,5-dichlorobenzoyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(2,5-dichloro-3-nitrobenzoyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(2-(4-chloro-o-tolyloxy)acetoxy)-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(tetrahydro-2-pyranyloxy)-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-methoxy-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(methylcarbamoyloxy)-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(2-methoxy-3,6-dichlorobenzoyloxy)-6-amino-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(methylsulfonyloxy)-6-nitro-5,7-dibromo-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(2-(4-chloro-o-tolyloxy)acetoxy)-5-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-(2,4-dichlorophenoxyacetoxy)-7-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-methoxy-5-(methylsulfonyl)-2-(pentafluoroethyl)-1H-imidazo(4,5-b)pyridine.

1-ethoxy-7-fluoro-2-(difluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-propionyloxy-5-chloro-6-bromo-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine.

1-octanoyloxy-7-amino-2-(difluorochloromethyl)-1H-imidazo(4,5-b)pyridine,

1-methoxy-7-nitro-2-(difluorochloromethyl)-1H-imidazo(4,5-b)pyridine.

1-allyloxy-2,7-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-cyclohexyloxy-5,6,7-trinitro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-benzyloxy-5,6,7-trichloro-2-(difluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-phenethoxy-5,6-bis(difluoromethyl)-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-acetoxy-2,5,6-tris(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-acryloyloxy-5,6-bis(difluorochloromethyl)-1H-imidazo(4,5-b)pyridine.

1-(tetrahydro-2-pyranyloxy)-5,6-bis(ethylsulfonyl)-2-(trifluormethyl)-1H-imidazo(4,5-b)pyridine.

1-benzoyloxy-6-methyl-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

1-methoxy-6-(perfluorooctyl)-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.

The compounds of the present invention are adapted to be employed as herbicides. The compounds can be utilized to achieve broad herbicidal action; hence, in its broadest sense, the present invention is directed to a method which comprises applying to a plant part, which can be a stem, leaf, flower, fruit, root, or seed or other similar reproductive unit of a plant, a growth-inhibiting amount of one of the compounds of the present invention. However, the compounds can also be utilized to take advantage of selective patterns of herbicidal activity.

It is not critical to the practice of the present invention that complete destruction of undesirable vegetation be obtained, it being adequate if the growth of the unwanted vegetation is merely inhibited. Especially where selective action is sought, inhibition falling short of actual killing is adequate, particularly when combined with naturally occurring conditions such as limited moisture and the like which more adversely affect the vegetation selectively inhibited than the crop plant.

The compounds of the present invention are suited to a wide variety of herbicidal applications. Thus, for example, at rates which evoke the selective action of the compounds, which rates are defined more completely hereinbelow, the compounds can be used as selective herbicides in crop plants, such as, for example, cotton, corn, sorghum, soybeans, and the like. In such use, application can be made preemergent to both crops and weeds, or, preferably by means of a directed spray application technique postemergent to the crop plant but both preemergent and postemergent to the weeds. In another application, the compounds can be used to give broad herbicidal action on non-crop land, including intermittently non-crop strips of contour-farmed land. For such usage on so-called fallow land, application can be made in spring to suppress vegetative growth until a fall or following spring planting, or in the fall to suppress vegetative growth until a spring or following fall planting. Furthermore, in another application, the present compounds can be utilized to control weeds in tree crop plantings, such as plantings of the various citrus trees. In all of these various applications, and yet others for which the present compounds are suited, another advantage is that the compounds need not be disced into the soil being treated, it being adequate if one of the compounds, or a formulation containing one of the compounds, is merely spread onto the top surface. However, where desired or convenient, the compounds can be disced into, or otherwise mechanically mixed with the soil. In addition to the foregoing terrestrail embodiments, the present compounds can also be utilized as aquatic herbicides.

The practice of the present invention in any of its numerous embodiments can in some instances be carried out with unmodified compound; however, for good results, it is generally necessary that the compound be employed in modified form, that is, as one component of a composition formulated to implement the plant growth-inhibiting efects. Thus, for example, the active agent can be mixed with water or other liquid or liquids, preferably aided by the usage of a surface active agent. The active agent can also be incorporated on a finely divided solid, which can be a surface active substance, to yield a wettable powder, which can subsequently be dispersed in water or other liquid, or incorporated as part of a dust which can be applied directly. Other methods of formulations are known in the art and can be employed in implementing the present invention.

In carrying out the novel method of the present invention, the exact amount of the active agent employed is not critical and will vary, depending upon the type of growth-inhibiting effect desired, the identity of the plants concerned, the particular active agent used, weather conditions, and the like. In general, a broad growth-inhibiting effect is obtained with rates of from 3-5 to 20 pounds or more of active agent per acre, and such rates are suitable and effective for control of vegetative growth on fallow land. When it is desired to obtain a selective growth-inhibiting effect on weeds in areas containing crop plants such as corn, soybeans, and cotton, rates of from 0.25 or less to 5 pounds generally give good results. When in the typical mode of operation, the active agent is employed as a composition comprising the agent, the exact concentration of active agent in the composition is not critical, except that the concentration and total mount of formulation employed be adequate to supply the appropriate amount of active agent on a per acre basis. In general, good results are obtained when employing formulations containing the active agent in a concentration of from 0.5 to 10 percent or higher, in the instance of a liquid formation; and in a concentration of from 1.0 to 5.0 percent or higher, in the instance of a dust, powder, granule, or the like. More concentrated formulations can be prepared and are often preferred in that they can serve, depending upon the particular application contemplated and the particular concentration, both as a concentrated formulation for purposes of shipment, storage, and the like, and as an ultimate treating composition. Thus, for example, formulations often preferably contain a surface active agent and the present active agent, the latter being present in an amount of from 0.5 to 99.5 percent, by weight; or an inert, finely divided solid and the present active agent, the latter being present in an amount of from 1.0 to 99.0 percent, by weight. Such formulations, as indicated, can be employed directly in certain applications, but can also be diluted and subsequently employed in many other applications.

Liquid compositions containing the desired amount of active agent are prepared by dissolving the substance in a liquid with or without the aid of a surface active dispersing agent such as an ionic or non-ionic emulsifying agent. Most preferably, the subject compound is dissolved in water or in an organic liquid carrier, aided by the use of a surface active dispersing agent. Suitable such organic liquid carriers include agricultural spray oils and the petroleum distillates such as diesel fuel, kerosene, fuel oil naphthas and Stoddard solvent. The choice of dispersing and emulsifying agent and the amount thereof employed is dictated by the nature of the composition and by the ability of the agent to facilitate the dispersion of the active agent in the carrier to produce the desired composition. Dispersing and emulsifying agents which can be employed in the compositions include the condensation products of alkylene oxides with phenols and organic acids, alkyl aryl sulfonates, polyoxyalkylene derivatives or sorbitan esters, complex ether alcohols, and the like. Representative surface active agents which are suitably employed in implementing the present invention are identified in U.S. Pat. Nos. 3,095,299, second column, lines 25-36, 2,655,447, column 5, and 2,412,510, columns 4 and 5.

In the preparation of dust compositions, the active ingredient is intimately dispersed in and on a finely divided solid such as clay, talc, chalk, gypsum, limestone, vermiculite fines, perlite, and the like. In one method of achieving such dispersion, the finely divided carrier is mechanically mixed or ground with the active agent.

Similarly, dust compositions containing the toxicant compounds can be prepared with various of the solid surface active dispersing agents such as bentonite, fuller's earth, attapulgite and other clays. Depending upon the proportions of ingredients, these dust compositions can be employed as concentrates and subsequently diluted with additional solid surface active dispersing agents or with chalk, talc, or gypsum and the like to obtain the desired amount of active ingredient in a composition adapted to be employed for the suppression of the growth of the plants. Also, such dust compositions can be dispersed in water, with or without the aid of a dispersing agent, to form spray mixtures.

Formulations containing the present active agent are often advantageously further modified by incorporation therein of an effective amount of a surfactant which facilitates the dispersion and spreading of the formulation of the plant leaf surfaces and the incorporation of the formulation by the plant.

In accordance with the present invention, the active agent can be dispersed in soil or other growth media in any convenient fashion. Applications can be carried out by simply mixing with the media, by applying to the surface of soil and thereafter draggin or discing into the soil to the desired depth, or by employing a liquid carrier to accomplish the penetration and impregnation. The application of spray and dust compositions to the surface of soil, or to plant parts or the above ground surfaces of plants can be carried out by conventional methods, e.g., power dusters, boom and hand sprayers and spray dusters, whether surface or air-borne. However, while such conventional modes of application can be used, they are not required. As above noted, it is an advantage of the present invention that the compounds serving as active agent are active and effective as herbicides when merely placed on the surface of the soil, without any additional step to assist incorporation. Thus, the compounds are of substantially the same efficiency regardless of whether they are applied to the surface only, or whether they are applied to the surface and subsequently disced into the soil.

In a further method, the distribution of the active agent in soil can be accomplished by introducing the agent into the water employed to irrigate the soil. In such procedures, the amount of water is varied with the priority and water holding capacity of the soil to obtain a desired depth of distribution of the agent.

In addition, the present method also comprehends the employment of an aerosol composition containing one or more of the present active agents as an active compound. Such a composition is prepared according to conventional methods wherein the agent is dispersed in a solvent, and the resultant dispersion mixed with a propellant in liquid state. Such variables as the particular agent to be used and the nature of the vegetation which is to be treated will determine the desirability of the solvent and concentration of the agent therein.

Satisfactory results are obtained when the active agent of the present invention, or a composition comprising such active agent, is combined with other agricultural materials intended to be applied to plants, plant parts, or their habitats. Such materials include fertilizers, fungicides, nematocides, insecticides, other herbicides, soil conditioning agents, and the like.

The following further examples illustrate the herbicidal utility of the compounds of the present invention.

EXAMPLES 62-70

Various of the compounds of the present invention were evaluated for preemergent application to various crop and weed species. Each compound was formulated by dissolving it in a 1:1 mixture of acetone and ethanol containing a small amount of a blend of sulfonate nonionic emulsifying agents; the solution was then diluted first with deionized water, then serially with deionized water containing 1000 ppm. of the blend of emulsifiers. The resulting solutions contained the subject compound in various amounts, the emulsifier blend in a concentration of 0.1 percent.

A soil was prepared consisting of one part masonry sand and one part shredded top soil blended together in a cement mixer. One gallon of this soil was placed in a 21.5 × 31.5 cm. galvanized flat and was patted down with a bench brush until level. A three-row marker was used to make 2 1/2 cm. deep furrows in approximately two-fifths of the flat. Crop seeds consisting of four kernels of corn, five cotton seeds and five soybean seeds were placed in these furrows. A four-row template was then placed on the remaining soil and the indicated approximate numbers of each of the following seeds were planted, one species to each section: foxtail (millet), 80-100 seeds; velvetleaf (40-50 seeds); rough pigweed (150-250 seeds); and large crabgrass (100-150 seeds).

Sufficient soil was added to cover the entire flat. Thus, the weed seeds were covered to a depth of about 6 mm. and the crop seeds were covered to a depth of about 3 cm.

In assaying the effect of the composition as preemergent herbicides, a flat prepared as above, taken either on the day of planting or on the next day, was placed in a chamber equipped with a turntable and an air exhaust. The herbicidal composition was applied to the flat with a modified DeVilbiss atomizer hooked to an air source. Twelve and one-half milliliters of the composition under test were applied to each flat either on the day of planting or on the succeeding day. Injury ratings and observations as to type of injury were made eleven to twelve days after treatment. The injury rating scale used was as follows:

O--no injury

1-- slight injury

2--moderate injury

3--severe injury

4--death

When more than one determination was carried out at a given rate, an average value was calculated for the injury rating.

In the following table setting forth the results of the evaluation, column 1 gives the name of the compound under test; column 2, the rate in pounds per acre at which the compound was applied to the test flat; and the remaining columns, the injury to the particular plant seeds or seedlings as measured by the foregoing scale.

                                      TABLE I                                      __________________________________________________________________________     Injury Rating on Preemergent Treatment                                                       Lbs./                            Velvet-                         Compound      Acre Corn                                                                              Cotton                                                                             Soybean                                                                             Crabgrass                                                                            Pigweed                                                                             Foxtail                                                                             leaf                            __________________________________________________________________________     1-Methoxy-6-chloro-2-                                                                        8    2  4   3    3     3    4    3                               (trifluoromethyl)-1H-                                                                        4    2  2   1    4     4    4    4                               imidazo(4,5-b)pyridine                                                                       2    1  1   1    4     3    4    4                                             1    0  1   0    3     3    3    4                               1-Acetoxy-6-chloro-2-                                                                        8    1  --  --   3     2    3    3                               (trifluoromethyl)-1H-                                                                        4    1  0   0    2     2    3    3                               imidazo(4,5-b)pyridine                                                                       2    0  0   1    1     2    3    3                               1-Ethoxy-6-chloro-2-                                                                         8    3  --  --   3     4    4    --                              (trifluoromethyl)-1H-                                                                        4    0  0   1    4     3    4    --                              imidazo(4,5-b)pyridine                                                                       2    0  0   0    3     2    2    --                              1-Allyloxy-6-chloro-2-                                                                       8    3  --  --   4     4    4    --                              (trifluoromethyl)-1H-                                                                        4    1  0   0    4     3    4    --                              imidazo(4,5-b)pyridine                                                                       2    0  0   0    3     1    3    --                              1-Isopropoxy-6-chloro-2-                                                                     8    2  --  --   4     4    4    --                              (trifluoromethyl)-1H-                                                                        4    1  0   1    4     2    4    --                              imidazo(4,5-b)pyridine                                                                       2    0  0   0    2     1    3    --                              1-(Allylcarbamoyloxy-6-                                                                      8    2  --  --   3     3    4    --                              chloro-2-(trifluoro-                                                                         4    0  1   1    3     3    2    --                              methyl)-1H-imidazo-                                                                          2    1  2   1    2     0    2    --                              (4,5-b)pyridine                                                                1-Octanoyloxy-6-chloro-                                                                      8    2  --  --   3     4    4    --                              2-(trifluoromethyl)-1H-                                                                      4    1  4   1    4     2    4    --                              imidazo(4,5-b)pyridine                                                         1-(Methylcarbamoyloxy)-                                                                      8    1  --  --   3     3    4    --                              6-chloro-2-(trifluoro-                                                                       4    1  2   1    3     3    4    --                              methyl)-1H-imidazo-                                                                          2    0  1   1    1     3    4    --                              (4,5-b)pyridine                                                                1-Methoxy-5-chloro-2-                                                                        8    3  --  --   4     4    4    4                               (trifluoromethyl)-1H-                                                                        4    2  0   2    3     3    4    4                               imidazo(4,5-b)pyri-                                                                          2    0    0.5                                                                              --   3       3.5                                                                                 3.5                                                                               4                               dine                                                                           __________________________________________________________________________      NOTE: Dashes indicate species which were not tested.                     

EXAMPLES 71-76

Representative compounds of the present invention were evaluated for postemergent application to plants including corn and several weed species. The evaluation was carried out in accordance with the procedures of Examples 62-70 except that the test solutions were applied about 9-12 days after the preparation and seeding of the flats. The results are as set forth in the following table:

                                      TABLE II                                     __________________________________________________________________________     Injury Rating on Postemergent Treatment                                        Compound          Lbs./Acre                                                                             Corn                                                                              Crabgrass                                                                            Pigweed                                                                             Foxtail                                                                             Velvetleaf                         __________________________________________________________________________     1-Acetoxy-6-chloro-2-(tri-                                                                       8      4  4     4    4    4                                  fluoromethyl)-1H-imidazo-                                                                        4      4  4     4    4    4                                  (4,5-b)pyridine   2      4  4     4    4    4                                                    1      2  4     4    4    4                                  1-Ethoxy-6-chloro-2-(tri-                                                                        3      4  4     4    4    4                                  fluoromethyl)-1H-imidazo-                                                                        4      4  4     4    4    4                                  (4,5-b)pyridine   2      2  4     4    4    4                                                    1      1  4     4    3    4                                  1-(3,6-Dichloro-2-methoxy-                                                                       8      1  4     4    3    3                                  benzoyloxy)-6-chloro-2-(tri-                                                                     4      0  3     2    3    3                                  fluoromethyl)-1H-imidazo-                                                      (4,5-b)pyridine                                                                1-(Methylcarbamoyloxy)-6-                                                                        8      2  4     4    4    4                                  chloro-2-(trifluoromethyl)-                                                                      4      2  4     4    4    3                                  1H-imidazo(4,5-b)pyridine                                                                        2      2  4     4    3    4                                                    1      1    3.5 4    4      2.5                                                1/2    0  4     3    4    2                                                    1/4    0  4     3    3    2                                  1-Methoxy-6-amino-5,7-dibromo-                                                                   8      0  3     4    3    2                                  2-(trifluoromethyl)-1H-imidazo-                                                (4,5-b)pyridine                                                                1-(Methylcarbamoyloxy)-6-                                                                        8      3  4     4    4    4                                  chloro-5,7-dibromo-2-(tri-                                                     fluoromethyl)-1H-imidazo-                                                      (4,5-b)pyridine                                                                __________________________________________________________________________

Essentially the same results as those reported in foregoing Examples 62-76 are obtained when evaluating the other representative compounds of Examples 1-61 hereinabove.

EXAMPLES 77-87

Other studies were carried out, evaluating various compounds of the present invention for preemergent application. These studies were made with a greater variety of plant species, at lower rates of application. Formulation of the compounds, however, was carried out in the same manner as described in preceding examples.

Rating of the herbicidal effect was on a scale of 0-10, with 0 indicating no herbicidal effect, and 10 indicating nonemergence or death. In addition, the kind of herbicidal effect was observed and recorded in accordance with the following notation system:

A = abscission of leaves

B = burned

C = chlorosis

D = death

E = epinasty

F = formative effects other than epinasty

G = dark Green

I = increased plant growth

L = local necrosis

N = no germination

P = purple pigmentation

R = reduced germination

S = stunting

U = unclassified injury

    TABLE III        Lbs./        Morning-  Velvet- Foxtail  Barnyard Compound Acre Corn      Cotton Soybean Rice Peanut Corn Soybean glory Cocklebur leaf Millet      Ragweed Grass        1-Methoxy-6-chloro-2- 0.5 2SC 0 0 0 0 0 0 10D 4BC 3BC 5BC 8BC 8BC      (trifluoromethyl)-1H- 1.0 4SC 3B 5BC 4BC 0 2SC 3CB 10D 10D 7BC 9BC 10D      9BC imidazo(4,5-b)pyridine 2.0 5SC 7BC 9BC 6BC 3C 4SC 8CB 10D 10D 10D      10D 10D 9.5BC 1-Acetoxy-6-chloro-2- 0.5 0 0 0 0 0 0 0 10D -- 4BC 4BC 8BC      2BC (trifluoromethyl)-1H- 1.0 4SC 6BC 5BC 4BC 0 3SC 6BC 10D 10D 8BC 5BC      10D 4BC imidazo(4,5-b)pyridine 2.0 5SC 10D 10D 7BC 3C 6SC 9BC 10D 10D      9BC 9.5BC 10D 8.5BC 1-Ethoxy-6-chloro-2- 0.5 0 0 0 0 0 0 0 2BC 0 0 0 8BC      0 (trifluoromethyl)-1H- 1.0 0 0 0 0 0 0 0 10D 0 7BC 8BC 10D 8BC imidazo(4      ,5-b)pyridine 2.0 2SC 0 6BC 5BC 0 3SC 9BC 10D 10D 9BC 10D 10D 9BC      1-Benzyloxy-6-chloro-2- 0.5 0 0 0 0 0 0 0 0 0 0 0 4BC 0 (trifluoromethyl)      -1H- 1.0 0 0 0 0 0 0 0 2SC -- -- 5SC 3BC 4BC imidazo(4,5-b)pyridine 2.0      0 0 0 0 0 0 0 5BC 0 3SC 3SB 3BC 4BC 1-Allyloxy-6-chloro-2- 0.5 0 0 0 0 0      0 0 9BC 0 4BC 0 6BC 3BC (trifluoromethyl)-1H- 1.0 0 0 0 0 0 0 0 10D 0      8BC 7BC 9BC 8BC imidazo(4,5-b)pyridine 2.0 0 0 0 3BC 0 0 4BC 10D 5BC      8.5BC 9.5BC 9BC 9BC 1-Isopropoxy-6-chloro-2- 0.5 0 0 0 0 0 0 0 8BC 2C      2BC 0 6BC 0 (trifluoromethyl)-1H- 1.0 0 0 0 0 0 0 0 10D 2C 2BC 2S 9BC      4BC imidazo(4,5-b)pyridine 2.0 2SC 0 0 0 0 0 0 10D -- 6BC8.5BC9.5BC 9BC      1-(Allylcarbamoyloxy- 0.5 0 0 0 0 0 0 0 8BC 4BC 0 2S 6BC 0 6-chloro-2-(tr      ifluoro- 1.0 0 0 0 2BC 0 0 0 10D 10D 2BC 4BC 8BC 6BC methyl)-1H-imidazo-      2.0 0 5BC 5BC 6BC 2C 2SC 5BC 10D 10D 5BC 8BC 10D 8BC (4,5-b)pyridine      1-Octanoyloxy-6-chloro- 0.5 0 0 0 0 0 0 0 7BC -- 0 0 5BC 0 2-(trifluorome      thyl)-1H- 1.0 0 3C 5BC 3SB 0 0 2C 10D -- 4BC 4BS 9BC 6BC imidazo(4,5-b)py      ridine 2.0 3SC 7BC 7BC5BC 0 4SC 7BC 10D 10D 9BC 8BC 9.5BC 7BC 1-(2-Methox      y-3,6-dichloro- 0.5 0 3F 7F 6F 6F 0 8F 7F 10D 2F 2S 8F 5FS benzoyloxy)-6-      chloro-2- 1.0 2S 5F 10D 8F 10D 0 10D 8F -- 8F 3SF 10D 4FS (trifluoromethy      l)-1H- 2.0 4S 9F 10D 9F 9F 1S 10D 10D 10D 10D 4SF 10D 5FS imidazo(4,5-b)p      yridine 1-(Methylcarbamoyloxy)-6- 0.5 0 0 0 0 0 0 0 10D -- 4BC 2BC 9BC      5BC chloro-2-(trifluoro- 1.0 2SC 3SC 4BC 4BC 0 1SC 3BC 10D 10D 7BC 8BC      10D 4BC methyl)-1H-imidazo- 2.0 4SC 8BC 10D 6BC 0 5SC 10D 10D 10D 10D      10D 10D 10D(4,5-b)pyridine 1-Ethoxy-2,6-bis(trifluoro- 0.5 0 0 0 0 0 0 0      7BC -- 0 0 0 0 methyl)-1H-imidazo(4,5-b)- 1.0 0 0 0 0 0 0 0 10D -- 2BC 0      7BC 2S pyridine 2.0 3SC 2SC 4BC 2BC 0 5SC 8BC 10D 10D 4BC 9BC 9BC 3S      Control  0 0 0 0 0 0 0 0 0 0 0 0 0 Control  0 0 0 0 0 0 0 0 0 0 0 0

EXAMPLE 88

1-Methoxy-6-chloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine was evaluated under field conditions. The compound was formulated in conventional procedures and applied as a soil surface spray to beds seeded with corn and selected weed species. The evaluations were carried out in a sub-tropical climate; there having been no rainfall in the first seven days following application, 1/2 inch of sprinkler irrigation was applied. Observations were made periodically for emergence, corn injury, and weed control. The results were as expressed in the following table, with date of observation expressed as the number of days from the day of seeding and compound application.

                                      TABLE IV                                     __________________________________________________________________________                                        Percent weed control                                                           All Observations Day 17                     __________________________________________________________________________                                        .                                                       Rate                                                                               Emergence.sup.a                                                                          Crop Injury.sup.c     Morn-   Black                              (Lbs./                                                                             Day Day                                                                               Day                                                                               Day                                                                               Day                                                                               Day                                                                               Prickly                                                                            Venice                                                                             Common                                                                              ing-                                                                               Foxtail                                                                            night-                                                                             Pig-               Compound    Acre)                                                                              5   7  11 11 17 38 sida                                                                               mallow                                                                             purslane                                                                            glory                                                                              millet                                                                             shade                                                                              weed               __________________________________________________________________________     1-methoxy-6-chloro-2-                                                                      1   97  90 89 0.0                                                                               0.0                                                                               0.0                                                                               98  90  100  89  98  100 100                (trifluoromethyl)-1H-                                                          imidazo(4,5-b)pyridine                                                                     1.5 97  89 87 0.0                                                                               0.3                                                                               0.0                                                                               99  97  100  100 99  100 100                            2   72  94 95 0.0                                                                               0.7                                                                               0.0                                                                               99  96  100  91  99  100 100                            3    100+                                                                              100                                                                               98 0.3                                                                               2.3                                                                               1.7                                                                               100 100 100  96  100 100 100                            4   96  85 83 2.0                                                                               3.7                                                                               4.3                                                                               100 100 100  100 100 100 100                Control     0   100 100                                                                               100                                                                               0.0                                                                               0.0                                                                               0.0                                                                                0   0   0    0   0   0   0                                 (72).sup.b                                                                         (108)                                                                             (109)       (14.6).sup.d                                                                       (5.6)                                                                              (3.8)                                                                               (5) (24.5)                                                                             (2.6)                                                                              (4.1)              __________________________________________________________________________      .sup.a Emergence expressed as a percent of the control.                        .sup.b Number of emerged corn seedlings per 15 feet of row.                    .sup.c Crop injury on a 0 - 10 scale where 0 = no injury, 1 - 3 = slight,      4 - 6 = moderate, 7 - 9 = severe, and 10 - death of all plants.                .sup.d Weeds/sq.ft. based on 5 one sq. ft. counts per plot.              

As noted above, the compounds of the present invention can be used in conjunction with other agricultural materials, including other herbicides. Thus, in one embodiment, the present invention is directed to a method which comprises applying essentially simultaneously to a plant part an amount of a first substance which is:

1-methoxy-6-chloro-2-trifluoromethyl-1H-imidazo(4,5-b)pyridine,

1-methoxy-5-chloro-2-trifluoromethyl-1H-imidazo(4,5-b)pyridine, or

1-methoxy-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine;

and an amount of a second substance which is:

alachlor,

atrazine,

butylate,

2-chloro-4-(1-cyano-1-methylethylamino)-6-ethylamino-s-triazine,

dalapon,

dinoseb,

diuron,

Eptc,

linuron,

oryzalin,

propachlor,

propazine,

simazine,

trifluralin, or

Tca,

the amounts being such as to effect, in combination, growth inhibition. This embodiment of the present invention also comprehends a combination of the first and second substances, which combination is useful in implementing the method.

The substances serving as the second substance of the present herbicidal methods and combinations are in every instance known compounds. For a convenient compilation of information and references on these and other known herbicides, attention is directed to the Herbicide Handbook of the Weed Society of America, sec. ed., published by the W. F. Humphrey Press, Inc., Geneva, New York, 1970, and available from Weed Science Society of America, Department of Agronomy, University of Illinois, Urbana, Illinois 61801.

The known herbicides serving as the second substance are generally crystaline solids, typically white in color; the exceptions are butylate (an amber liquid); EPTC (a light yellow-colored liquid); and dinoseb (which may exist as either a dark brown solid or a dark orange liquid, depending on temperature). Each of these compounds is individually effective at a range of rates, dependng upon the particular substance, the particular use (for example, whether a selective or general herbicidal effect is sought), and the type of soil and other growing conditions. The generally established rate ranges for these known herbicides, when used individually, are as follows:

    ______________________________________                                                            Established Rate                                            Compound           in Lbs./Acre                                                ______________________________________                                         alachlor           1 - 4                                                       atrazine           2 - 4                                                       butylate           3 - 4                                                       2-chloro-4-(1-cyano-1-methyl-                                                  ethylamino)-6-ethylamino-                                                      s-triazine         1 - 4                                                       dalapon            .75 - 20                                                    dinoseb            .75 - 12                                                    diuron             0.6 - 6.4  (selective)                                                          4 - 16    (general)                                        EPTC               2 - 6                                                       linuron            0.5 - 3    (selective)                                                         1 - 3      (non crop)                                       oryzalin           1 - 4                                                       propachlor         3 - 6                                                       propazine          1 - 4                                                       simazine           2 - 4                                                       trifluralin        0.5 - 2                                                     TCA                 4 - 30    (selective)                                                          50 - 200  (general)                                        ______________________________________                                          (Herbicide Handbook of the Weed Society of America, supra).              

In employing these known herbicides in combination with the herbicides of the present invention, the precise ratio of the herbicidal agents to one another is not critical. It is generally preferred that the known herbicide be used in an amount within its established rate range for individual use as sole herbicidal agent, although because of the herbicidal effect attributable to the ether, lesser amounts within the established rate range or amounts below the established rate range are appropriate. Thus, amounts below the median of the established rate range generally give good results in combination with the specified ethers. However, each of the ether and known herbicide components should be employed in an amount which, if employed individually as sole herbicidal agent, would exert at least a minimal plant-growth inhibiting effect. In the case of alachlor, atrazine, and propachlor, for example, the established rate ranges are 1-4 lbs./acre of alachlor, 2-4 lbs./acre of atrazine, or 3-6 lbs./acre of propachlor; but good results generally are obtained in the present combinations at application rates of 2.5 lbs./acre or less of alachlor, 3 lbs./acre or less of atrazine, or 4.5 lbs./acre or less of propachlor. For the specified ethers serving as the first component, application rates of 0.25-4 lbs./acre are desirable for selective activity, and preferred rates for selective activity are generally 1-2.5 lbs./acre.

The substances can be administered separately, although preferably essentially simultaneously, and this mode of administration is sometimes preferred. Thus, for example, different herbicide may require different modes of applications which preclude a single application. In particular, each of butylate and EPTC is preferably applied to corn prior to planting and with mechanical mixing into the soil. The ethers of the present invention are preferably applied to corn immediately after seeding but without mechanical mixing. Thus, separate administration is sometimes preferred in order to make best utilization of the respective herbicidal properties. Where separate administration is preferred, the exact interval between applications is not critical; but optimal results generally are obtained when the respective administrations are essentially simultaneously, such as within several minutes to not more than within several hours of one another. The time interval between applications is largely dictated by the practicalities of agricultural practices.

Generally, however, it is preferred that both substances be formulated as a single formulation. The formulation is conducted in accordance with conventional procedures, utilizing such adjuvants as surface-active agents, inert finely-divided solids, and the like. Reference is made to the discussion hereinabove concerning formulation of the compounds of the present invention, generally. Where the objective is selective herbicidal activity, it is generally preferred that the specified ether comprise at least 40 percent by weight of the total herbicidally-active component.

EXAMPLES 89-103

1-Methoxy-6-chloro-2-trifluoromethyl-1H-imidazo(4,5-b)-pyridine was evaluated in combination with each of a number of known herbicides. The evaluation was conducted in each case in accordance with the standard screening procedures described in preceding examples, each of the herbicides being applied separately but within rapid succession (within an interval of not longer than about 5 minutes).

The above results observed were as set forth in the following tables.

    TABLE V       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-  1H-IMIDAZO(4,5-b)P      YRIDINE ("A") WITH ALACHLOR ("B")         Rates                Lbs./ Morning  Foxtail Rag- Barnyard Large Pig-       Velvet  Jimson Johnson Lambs Compounds Acre Glory Corn Millet weed      Grass Crabgrass weed Sorghum Rice Leaf Corn Weed Grass Quarter        A + B 0.25 + 0.5  10D 0 10D 9SB 10N 9.5RS 9.5RS 3SB 9SR 4SB 0 6SB 9SB      9S " 0.25   1   10D 0 10D 9SR 10N 9.9RS 10N 5SB 10N 7SB 0 10D 10D 10N "      0.25   2   10D 1S 10D 9.5RS 10N 10N 10N 9SF 10N 9SB 0 9BS 10D 10N " 0.25        4   10D 2S 10N 10D 10N 10N 10N 8SF 10N 9BS 2S 9BS 10D 10N " 0.5 + 0.5      10D 0 10D 10D 10N 9.5RS 9.5RS 3SB 8S 8SB 1S 8BS 9BS 10N " 0.5   1   10D      0 10N 10D 10N 10D 9.5RS 4BSF 8RS 8BSR 0 8BS 9.5BS 10N " 0.5   2   10D 3S      10D 9.5BSR 10N 10N 10D 8SF 10N 9BS 0 9BS 9.5BS 9RS " 0.5   4   10D 3S      10N 10N 10N 10N 10N 9FSR 9.8RS 9.5BS 2S 9.5BS 10N 10N "   1 + 0.5 10D      2SB 10D 10D 10N 9.5BS 9.5RS 7BS 8BSR 9BS 0 9BS 7BS 9RS " 1   1 10D 1S      10D 10D 10N 9.8RS 9.8RS 8BS 9RS 10D 3S 9BS 10D 10N " 1   2 10D 3S 10N      9.8RSB 10N 9.8RS 10N 8BSF 9.5RS 10D 0 9.5BS 10D 10N " 1   4 10D 3S 10D      9.5BSR 10N 10D 10N 9BSF 9.5RS 9SB 2S 9.5BS 10D 10N "   2 + 0.5 10D 3S      10D 8S 10N 9.8RS 9.5RS 9.5BS 7SB 10D 3S 9.5BS 9BS 9.8RS " 2   1 10D 1S      10D 9.5RS 10N 10N 9.8RS 9 9RS 8BS 1S 9.8BS 9BS 10N " 2 +  2 10D 0 10D      9.8RS 10N 10N 10N 9BS 10D 9.5BS 1SB 9.5BS 10D 10N " 2   4 10D 3S 10D 10D      10N 10N 10N 9.5BSF 10N 9.5BS 4SB 9.8BS 10D 10N Control 0    0 0 0 0 0 0      0 0 0 0 0 0 0 0

    TABLE VI       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-1H-  IMIDAZO(4,5-b)P      YRIDINE ("A") WITH ATRAZINE ("B")         Rates                Lbs./ Morning Pig- Rag-  Velvet Lambs Jimson      Barnyard  Large  Foxtail  Johnson Compounds Acre Glory weed weed Corn      Leaf Quarter Weed Grass Rice Crabgrass Corn Millet Sorghum Grass        A + B 1/4 1/4 8SD 9RS 8RS 0 3BS 7RS 8.5SB 5BS 2BS 4S 0 3S 0 2S " 1/4      1/2 10D 9.5RS 8RSD 0 5BS 7RSD 9SD 8SD 3BS 4S 0 4BS 0 2S " 1/4 1 9.5SD      10N 8RSD 0 7SD 7RS 9SD 9.5SD 3BS 6S 0 4BS 0 4BS " 1/4 2 10D 9.5RS 9.5RS      0 9.5SD 7RS 9.5SD 9.5SD 3BS 8S 0 7SD 0 4BS " 1/2 1/4 10D 9.5RS 6.5SD 0      7SD 7.5RS 9SD 9SD 3BS 7RS 0 8SD 0 4BS " 1/2 1/2 10D 9RS 9SD 0 7SD 5RS      9.5SD 9.5SD 4BS 7RS 0 7SD 0 7SD " 1/2 1 10D 9.5RS 9.5RSD 1S 6SD 6.5RS      9SD 9SD 3BS 8SD 0 8.5SD 0 6.5SD " 1/2 2 10D 9RS 9.5RSD 0 9SD 7RS 8.5SD      10D 3BS 9SD 0 9.5SD 0 6.5SD " 1 1/4 10D 9RS 9SD 0 6.5SD 7RS 9SD 9.5SD      3BS 9.5SD 0 10D 3BS 7SD " 1 1/2 10D 9.5RS 9.5SD 0 9SD 7RS 9.5SD 9.5SD      2BS 9.5SD 0 10D 4BS 8SD " 1 1 10D 9.5RS 10D 0 9SD 8RS 9.5SD 10D 3BS      9.5SD 0 10D 4BS 7SD " 1 2 10D 9.5RS 10D 0 9SD 7RSD 9.5SD 10D 3BS 9.5SD 0      10D 3BS 9SD " 2 1/4 10D 9.5RS 9SD 1S 9.5SD 7RS 9.5SD 10D 3BS 9.5SD 0 10D      7SD 9.5SD " 2 1/2 10D 9.5R 10D 0 9.5SD 7.5RS 9.5SD 9.5SD 4BS 10D 0 10D      8SD 9SD " 2 1 10D 9.5RS 10D 2S 10D 8RS 9.5SD 9.5SD 5BS 9.5SD 1S 10D 8SD      9SD " 2 2 10D 9.5RS 10D 2S 10D 8RS 10D 10D 4BS 9.5SD 0 10D 7SD 9SD      Control -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Control -- -- 0 0 0 0 0 0 0 0      0 0 0 0 0 0 Control -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE VII       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-  1H-IMIDAZO(4,5-b)P      YRIDINE ("A") WITH BUTYLATE ("B")            Fox-             Rates Morn-  tail  Barn- Large  Lbs./ ing  Mil-      Rag- yard Crab- Pig-   Velvet  Jimson Johnson Lambs Compounds Acre Glory      Corn let weed Grass grass weed Sorghum Rice Leaf Corn Weed Grass      Quarter   A + B 0.25 + 1.0 10D 0  7SF 5SB 3S 4SB 9.5BS 9SF 0 10D 0 4SF      9SR 10D " 0.25   2.0 6SB 0  9SF 6SB 8S 6SB 9BS 10D 3S 10D 0 6SB 9.5RS      10D " 0.25   3.0 10D 0  9SBF 4SB 8SB 10D 9BSR 10D 7S 10D 0 7SB 10D 10D "      0.25   4.0 10D 0  9SB 8SB 8SB 10D 10D 10D 9SB 10D 0 7SB 10D 10D " 0.5 +      1.0 10D 1S 6SB 9.5BS 7SB 5SB 8BS 9SBF 3S 10D 2S 9BS 9RSB 10D " 0.5   2.0      9BS 1S 8BS 10D 8SB 9.5RS 10D 10D 6S 10D 1S 8BS 9RS 10D " 0.5   3.0 10D      3S 9.5BS 9.5RS 10D 10D 10D 10D 9.5S 10D 1S 9BS 10D 10D " 0.5   4.0 10D      4S 9.5BSR 9.5BSR 10D 10D 10D 10D 9.5S 10D 3S 9BS 10D 10D " 1.0 + 1.0 10D      5S 10D 10D 9.5BS 9BS 9.5BS 9.5BS 3B 10D 4S 9BS 9BS 10D " 1.0   2.0 10D      5S 10D 10D 9.5BS 10D 10D 10D 8S 10D 4S 9BS 10D 10D " 1.0   3.0 10D 4S      10D 10D 8BS 8BS 9BS 10D 5S 10D 3S 7BS 9.5BS 10D " 1.0   4.0 10D 3S 10D      10D 9.5BSR 9.5BS 9.5FS 9SF 7S 10D 3S 9BS 10D 10D " 2.0 + 1.0 10D 5S 10D      10D 9.5BS 9BS 9BS 8BSF 3B 10D 5SB 8SB 9BS 10D " 2.0   2.0 10D 5S 10D 10D      9.5BS 10D 8S 9.5BSF 5S 10D 6SB 8BS 9BSR 9SB " 2.0 +  3.0 10D 6SB 10D 10D      10D 9.5BS 9.5SB 10D 8S 10D 5S 8BS 9.5RS 10D " 2.0   4.0 10D 6SB 10D 10D      10D 10D 9.5BS 10D 9S 10D 6SB 9BS 10D 10D Control 0 0 0 0 0 0 0 0 0 0 0 0      0 0 0

    TABLE VIII       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-1H-  IMIDAZO(4,5-b)P      YRIDINE ("A") WITH 2-CHLORO-4-(1-CYANO- 1-METHYLETHYLAMINO)-6-ETHYLAMINO-      s-TRIAZINE ("B")            Fox-             Rates Morn-  tail  Barn- Large  Lbs./ ing  Mil-      Rag- yard Crab- Pig-   Velvet  Jimson Johnson Lambs Compounds Acre Glory      Corn let weed Grass grass weed Sorghum Rice Leaf Corn Weed Grass      Quarter   A + B 0.25 + 0.25 10D 0 10D 10D 4SB 6SB 5S 3SB 4S 9BS 2S 9BS      7BS 8SB " 0.25   0.5  10D 3S 10D 10D 7SB 9.5BS 7S 8BS 9BS 9.5BS 2S 9.5BS      9.5BS 8SB " 0.25   1.0  10D 4S 10D 10D 9.5BS 10D 7SB 6SB 8BS 10D 3S 10D      10D 9.5BS " 0.25   2.0  10D 5S 10D 10D 10D 10D 10D 9.5BS 10D 10D 4SB      9.5BS 9.5BS 9.5BS "  0.5 + 0.25 10D 3S 10D 10D 8SB 7SB 6SB 6SB 8B 9BS 3S      9BS 9.5BS 8S " 0.5   0.5 10D 2S 10D 10D 8B 9.5SB 6SB 6SB8B 10D 2S 9BS      9.5BS 9SB " 0.5   1.0 10D 2SB 10D 10D 9.5SB 10D 9.5BS 9.5BS 10D 9.8BS      2SB 9.5BS 9BS 9SB " 0.5   2.0 10D 3SB 10D 10D 9.5BS 10D 9.5BS 9.8BS 10D      10D 2S 9.5BS 9.5BS 9SB "  1.0 + 0.25 9.5BS 2S 10D 10D 9.5BS 10D 8SB 7SB      7B 9.5BS 2S 9.5BS 9.5BS 9SB " 1.0   0.5 10D 2SB 10D 10D 9.5BS 10D 9.5BS      9.5BS 10D 10D 2S 9.5BS 10D 9S " 1.0   1.0 10D 2SB 10D 10D 9.5BS 9.8BS      9.5SB 9.5BS 10D 10D 2S 10D 9.5BS 9.5SB " 1.0   2.0 10D 4SB 10D 10D 9.5BS      10D 9.5BS 10D 10D 9.8BS 3S 9.5BS 10D 9SB "  2.0 + 0.25 10D 2S 10D 10D      9.5BS 9.5BS 9.5BS 8SB 7BS 9.5BS 3S 9.5BS 9.5BS 9SB " 2.0   0.5 10D 5SB      10D 10D 10D 10D 9.5BS 9.5BS 10D 10D 5SB 9.5BS 10D 10D " 2.0 + 1.0 10D      4SB 10D 10D 10D 10D 9.8BS 10D 10D 10D 3SB 10D 10D 9SB " 2.0   2.0 10D      4SB 10D 10D 10D 10D 9.5BS 10D 10D 10D 5SB 10D 10D 10D Control 0 0 0 0 0      0 0 0 0 0 0 0 0 0 0

    TABLE IX       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL  1H-IMIDAZO(4,5-b)PY      RIDINE ("A") WITH DALAPON ("B")            Fox-             Rates Morn-  tail  Barn- Large  Lbs./ ing  Mil-      Rag- yard Crab- Pig-   Velvet  Jimson Johnson Lambs Compounds Acre Glory      Corn let weed Grass grass weed Sorghum Rice Leaf Corn Weed Grass      Quarter   A + B 0.25 + 0.75 3SBC 0 4SB 3S 0 2S 4S 0 0 3SB 0 0 0 0 " 0.25        1.5  2B 0 6BS 10D 0 0 4B 0 2S 3S 0 0 0 0 " 0.25   3.0  2B 0 9BS 10D 0      7SB 3BS 0 6SB 4S 0 4B 0 3S " 0.25   6.0  3SB 0 10D 9BS 3BS 8BS 4BS 3BS      5SB 3SB 0 4BS 0  -- "  0.5 + 0.75 6SB 0 8BSR 10D 2S 5SB 5SB 0 0 4S 0 7BS      3S 7SR " 0.5   1.5 9BS 0 9BS 10D 4BS 8BS 3B 1S 3S 6SB 0 8BS 0 6RS " 0.5       3.0 9BS 1S 10D 10D 5SB 7SB 3B 1S 5SB 7SB 0 6BS 2S 7RS " 0.5   6.0 10D 0      10D 9.5BS 7BS 8BS 10D 3SB 7BS 7SB 0 8BS 2S 7RS "  1.0 + 0.75 9.5BS 0 10D      10D 6BS 10D 6BS 3SB 5BS 9.5BS 0 10D 4S 6SR " 1.0   1.5 9.5BS 0 10D 10D      4SB 9BS 7BS 2SB 4B 10D 0 10D 3SB 7SR " 1.0   3.0 10D 0 10D 10D 5BS 9.5BS      9BS 3SB 5BS 10D 0 10D 6BS 7RS " 1.0   6.0 10D 4F 10D 10D 7BSR 10D 10D      6BSR 9BS 10D 4FS 10D 4SB 8S "  2.0 + 0.75 10D 0 10D 10D 4BS 7BS 9BS 8BS      6BS 9.5BS 2S 10D 8BS 10D " 2.0   1.5 10D 3S 10D 10D 9BS 10D 9BS 8BS 9BS      10D 3S 10D 7BS 10D " 2.0 + 3.0 10D 1S 10D 10D 9BS 10D 10D 9BS 9BS 10D 2S      10D 7BS 9RS " 2.0   6.0 10D 2S 10D 10D 9.5BS 10D 10D 6BS 8BS 10D 4SB      9.5BS 8BS 9RS Control 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE X       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-  1H-IMIDAZO(4,5-b)P      YRIDINE ("A") WITH DINOSEB ("B")            Fox-             Rates Morn-  tail  Barn- Large  Lbs./ ing  Mil-      Rag- yard Crab- Pig-   Velvet  Jimson Johnson Lambs Compounds Acre Glory      Corn let weed Grass grass weed Sorghum Rice Leaf Corn Weed Grass      Quarter   A + B 0.25 + 1.0  2B 0 0 7SB 0 2S 2S 0 0 35B 0 7SB 2S 5S "      0.25   2.0  5SB 0 2S 10D 0 0 2S 0 0 3SB 0 8BS 0 5S" 0.25   4.0  9BS 0 2S      10D 2S 2S 6S 0 0 3S 0 9BS 0 5S " 0.25   8.0  9BS 0 4S 10D 4SR 5RS 8SR 2S      3S 3S 1S 10D 2S 6S " 0.5 + 1.0 6SB 0 3SB 10D 5SB 8BS 8SR 2S 3BS 5SB 0      9.5BS 3SB 9SR " 0.5   2.0 10D 0 8BS 10D 4SB 6SB 9SR 1SB 1B 5SB 0 9.5BS      3SB 9SR " 0.5   4.0 10D 0 7SB 10D 4SB 8BSR 7SR 2SB 2SB 6SB 0 9.5BS 2SB      7SR " 0.5   8.0 10D 2S 7SB 10D 7SR 7SRB 6SR 3S 2SB 5SB 0 10D 2S 9SR "      1.0 + 1.0 10D 2S 10D 10D 9SB 9.5RS 10N 7BS 10D 10D 1S 9.5BS 8BS 10D "      1.0   2.0 10D 1S 10D 10D 9BS 10D 10D 8BS 4BS 7BS 1S 10D 6BS 10D " 1.0      4.0 10D 2SB 10D 10D 8BS 10D 10D 6BS 4BS 8BS 0 10D 7BS 10D " 1.0   8.0      10D 1S 7BS 10D 7BS 10D 9.5RS 4BS 6SB 10D 0 10D 6BS 10D " 2.0 + 1.0 10D      4SB 10D 10D 10D 10D 9SB 9BS 8BS 10D 4SB 10D 10D 10D " 2.0   2.0 10D 3S      10D 10D 10D 10D 10D 10D 8BS 10D 4SB 10D 9.5BS 10D " 2.0 + 4.0 10D 2S 10D      10D 9.5BS 10D 10D 9BS 8BS 10D 1S 10D 9.5BS 10D " 2.0   8.0 10D 3SB 10D      10D 10D 10D 10D 8BS 8BSC 10D 2S 10D 10D 10D Control 0 0 0 0 0 0 0 0 0 0      0 0 0 0 0

    TABLE XI       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-  1H-IMIDAZO(4,5-b)P      YRIDINE ("A") WITH DIURON ("B")            Fox-             Rates Morn-  tail  Barn- Large  lbs./ ing  Mil-      Rag- yard Crab- Pig-   Velvet  Jimson Johnson Lambs Compounds Acre Glory      CornLet weed Grass grass weed Sorghum Rice Leaf Corn Weed Grass Quarter        A + B 0.25 + 0.25 10D 0 4SB 10D 4BS 5SB 8BS 1B 1B 5BS 0 7BS 2SB 8SR "      0.25   0.5 6BSL 0 5BS 10D 9BS 8BS 9BS 2B 4B 8BS 0 9BS 3BS 9SR " 0.25      1.0  10D 0 8BS 10D 10D 9BS 9BS 3BC 3B 10D 3S 9BS 8BS 9SR " 0.25   2.0      10D 5BS 10D 10D 10D 9.5BS 9BS 4BS 7B 10D 5SB 9BS 9.5BS 1ON "  0.5 + 0.25      10D 2B 8BS 10D 7BS 8BS 9.5RS 3SB 4B 9BS 0 9BS 7BS 9RS " 0.5   0.5 9BS      2SB 10D 9.5BS 9BS 8BS 9BS 2S 4B 9BS 0 9BS 9.5BS 9.5RS " 0.5   1.0 10D 2S      10D 10D 10D 9BS 9.5BS 2SB 4B 10D 5SB 9.5BS 9RS " 0.5   2.0 10D 5SB 10D      10D 10D 9BS 9BS 3CSB 5B 10D 4SB 9BS 9BS 9RS "  1.0 + 0.25 9BS 2S 10D 10D      10D 9.5BS 9.5BS 3SB 4B 10D 2S 9.5BS 9.5BS 10N " 1.0   0.5 10D 4SB 10D      10D 10D 9.5BS 9.5BS 7BS 9B 10D 4SB 10D 10D 9.5RS "1.0   1.0 10D 7SB 10D      10D 10D 9.5BS 9.5BS 10D 9B 10D 8BS 9BS 10D 9.5RS " 1.0   2.0 10D 4SB 10D      10D 10D 9.5BS 9.5BS 10D 9.5B 10D 7BS 9.5BS 10D 9.5RS "  2.0 + 0.25 10D      5SB 10D 10D 10D 9.5BS 10D 9BS 9B 10D 4SB 9.5BS 10D 10N " 2.0   0.5 10D      7SB 10D 10D 10D 9.5BS 9.5BS 9.5B 9B 10D 6SB 9.5BS 10D 9.5RS " 2.0 + 1.0      10D 7SB 10D 10D 10D 9.5BS 10D 10D 9.5B 10D 6SB 9.5BS 10D 10N " 2.0   2.0      10D 7SB 10D 10D 10D 9.5BS 10D 9B9.5B 10D 8BS 9.5BS 10D 10N Control 0 0 0      0 0 0 0 0 0 0 0 0 0 0 0

    TABLE XII       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-  1H-IMIDAZO84,5-b)      PYRIDINE ("A") WITH EPTC ("B")             Fox-             Rates Morn-  tail  Barn- Large  Lbs./ ing  Mil-      Rag- yard Crab- Pig-   Velvet  Jimson Johnson Lambs Compounds Acre Glory      Corn let weed Grass grass weed Sorghum Rice Leaf Corn Weed Grass      Quarter   A + B 0.25 +1.0  10D 3S 9BS 8SB 7BS 6BS 8SB 10D 8S 10D 0 8BS      10D 9.5RS " 0.25   2.0  10D 2S 9BS 10D 9BSF 9.5RSB 10N 10N 10D 4S 9BS      10D 10N " 0.25   3.0  10D 7FS 9.5BS 10D 9BSF 10D 10N 10D 9.8RS 10D 4S      10D 10N 10N " 0.25   4.0  10D 8FS 10D 10D 9BSF 10D 10N 10D 10N 10D 7FS      9BSR 10N 9.5RS " 0.5 + 1.0 10D 1S 10D 10D 8BS 7BS 10D 10D 8BSR 10D 4S      9BS 10D 10N " 0.5   2.0 10D 5SF 10D 10D 9.5BSR 10D 10N 9.8RSF9.5RS 10D      4S 9BS 10D 10N " 0.5   3.0 10D 7FS 10D 10D 9.5BSF 10D 10N 10D 10N 10D      6SF 9.5BS 10D 9.8RS " 0.5   4.0 10D 8FS 10D 10D 9.8BS 10N 10N 10D 10N      10D 8FS 9BS 10D 10N " 1.0 + 1.0 10D 4S 10D 10D 9.8BS 9.5BS 9.5BSR 10D      8SB 9.5BS 4S 9.5BS 9.5BS 9RS " 1.0   2.0 10D 8SB 10D 10D 10D 10D 10N 10D      10D 10D 5S 9BS 10D 9.5RS " 1.0   3.0 10D 7SBF 10D 10D 10D 10D 10D 10D      10N 10D 8BSF 9.5BS 10D 9.5RS " 1.0   4.0 10D 7SB 10D 10D 10D 10D 10N 10D      10D 10D 8SBF 10D 10D 9.8RS " 2.0 + 1.0 10D 7SB 10D 10D 10D 10D 9.5RSB      10D 8SB 10D 7SB 9BS 10D 9.5RS " 2.0   2.0 10D 8SB 10D 9SB 10D 10D 9.5RSB      10D 10D 10D 7SB 10D 10D 10N " 2.0 + 3.0 10D 10D 10D 10D 10D 10D 10N 10D      10N 9.8BSR 9SB 10D 10D 9.8RS " 20   4.0 10D 10D 10D 10N 10d 10D 10N 10D      10D 10D 9BS 9.5BS 10D 9.8RS Control 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE XIII       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-  1H-IMIDAZO[4,5-b)P      YRIDINE ("A") WITH LINURON ("B")      Fox-             Rates Morn-  tail       Barn- Large  Lbs./ ing  Mil- Rag- yard Crab- Pig-   Velvet  Jimson      Johnson Lambs Compounds Acre Glory Corn let weed Grass grass weed      Sorghum Rice Leaf Corn Weed Grass Quarter        A + B 0.25 + 0.25 2SBC 2SB 8BS 10D 4BS 5S 9SB 0 2B 9BS 0 8BS 2SB 9.5RS      " 0.25   0.5 3SB 0 8BS 7BS 8BS 5S 9SB 0 2B 10D 0 8BS 9BS 10D " 0.25      1.0 4SB 0 10D 9BS 10D 9BS 10D 3BS 4B 10D 0 9BS 9BS 9SR " 0.25   2.0 9BS      3S 10D 10D 9.5BS 9BS 9S 4SB 4B 10D 4BS 8BS 9BS 8SR " 0.5 + 0.25 10D 3B      8BS 9BS 8BS 7SB 9BS 3B 3B 9BS 1S 9BS 7BS 9SRB " 0.5   0.5 5SB 0 8BS 9BS      9BS 7BS 10D 2S 2B 10D 0 9BS 9BS 9SR " 0.5   1.0 9BS 0 10D 9BS 9BS 8BS 9S      3S 3B 10D 2S 8BS 8BS 9SR " 0.5   2.0 10D 3S 10D 10D 10D 9.5BS 9.5BS 3SB      4B 10D 3S 9BS 9.5BS 9SR " 1.0 + 0.25 10D 2S 10D 10D 9.5BS 9.5BS 9.5BS      4SB 3B 9.5BS 2S 9.5BS 9.5BS 9SR " 1.0   0.5 10D 3S 10D 10D 10D 9BS 9.5BS      8B 4B 10D 3S 9.5BS 10D 9.5RS " 1.0   1.0 10D 4SB 10D 10D 10D 9.5BS 9.5BS      9BS 5B 10D 3S 9.5BS 9.5BS 9.5RS " 1.0   2.0 10D 6SB 10D 10D 10D 9.5BS      9.5BS 9.5BS 6B 10D 5SB 9.5BS 10D 10D " 2.0 + 0.25 10D 5S 10D 10D 10D      9.5BS 9.5BS 9.5BS 9B 10D 5SB 10D 10D 9.5RS " 2.0   0.5 10D 5SB 10D 10D      10D 9.5BS 9.5BS 9.5BS 8B 10D 7SB 9.5BS 9.5BS 9.5RS " 2.0 + 1.0 10D 6SB      10D 10D 10D 9.5BS 10D 9B 8B 10D 5SB 9.5BS 9.5BS 9.5RS " 2   2.0 10D 7SB      10D 10D 10D 9.5BS 9.5BS 10D 9BS 10D 6SB 10D 10D 9.5RS Control 0 0 0 0 0      0 0 0 0 0 0 0 0 0 0

    TABLE XIV       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)PY      RIDINE ("A") WITH ORYZALIN ("B")         Rates Morning    Velvet Lambs Jimson Barnyard  Large  Foxtail      Johnson Compounds Lbs./Acre Glory Pigweed Ragweed Corn Leaf Quarter Weed      Grass Rice Crabgrass Corn Millet Sorgham Grass        A + B 1/4 1/2 5S 6S 5S 6.5BS 5.5CS 10N 3CS 7RS 6.5CS 9.5RS 5CS 8.5SD      7BS 6.5BS " 1/4 1 5S 7.5RS 6.5CRS 7.5BS 6CS 9.5RS 6S 8.5RS 8CS 9.5RS 7BS      9SD 7.5BS 7BS " 1/4 2 9BSD 9RS 8RS 8BS 7CS 10N 6.5S 9RS 8CS 1ON 8BS      9.5RS 8BPS 8BSD " 1/4 4 9.5BSD 9RS 8.5RS 9BS 9BS 1ON 7BS 9.5RS 9BS 1ON      9BS 1OD 9BS 8.5BSD " 1/2 1/2 8BSD 8RS 8.5BSD 6BS 5CBS 9.5RS 5S 6.5RS      6.5CS 9RS 5BS 9BSD 6.5RS 7BSD " 1/2 1 9.5BSI 9.5RS 9BS 7BS 6.5BS 10N      9BSD 9RS 7.5BSC 1ON 7BS 10D 7BS 8SD "  1/22 9.5BSD 9.5RS 9BSD 7BS 8.5BSD      1ON 8BSD 9.5RS 8.5BS 10N 8BS 9.5SD 8.5BS 8BSD " 1/2 4 10D 9.5RS 9.5SD      8BS 8.5BSD 10N 9BSD 1OD 8.5BS 10N 7.5BS 10N 9BS 8BSD " 1 1/2 10D 9RS      9.5SD 4S 6BSD 9.5RS 9.5BSD 9SD 7BS 9.5SD 4S 10D 7BS 9BSD " 1 1 10D 9RS      9.5SD 7BS 7BSD 10N 9.5BSD 9SD 7BS 9.5RS 6S 9SD 5BS 9BSD " 1 2 9.5BSD 10N      9.5BSD 7BS 9.5BSD 10N 9BSD 10D 8BS 10N 7.5BS 10D 9SD 9.5SD "  1 4 10D      10N 10D 7BS 9.5BSD 10N 9.5BSD 10D 8.5BS 10N 8.5BS 10D 9BSD 9.5BSD " 2      1/2 10D 9.5RS 9.5SD 2.5BS 10D 10N 9.5SD 9.5RS 7SD 10N 3S 10D 7BS 10D " 2      1 10D 9.5SD 9.5SD 4BS 10D 9.5RS 9.5SD 10D 8BSD 10N 4.5BS 10D 7.5BSD 10D      " 2 2 10D 10N 9.5SD 6.5BS 10D 10N 10D 10D 8BSD 9.5SD 5.5S 10D 7.5BSD      9.5SD " 2 4 9.5SD 10D 10D 3.5S 9.5SD 10N 10D 10D 6.5BS 10N 5.5S 10D      8.5BSD 10D Control -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE 2 XV       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)      PYRIDINE ("A") WITH PROPACHLOR ("B")         Rates Morning  Foxtail  Barnyard Large    Velvet  Jimson Johnson      Lambs Compounds Lbs./Acre Glory Corn Millet Ragweed Grass Crabgrass      Pigweed Sorghum Rice Leaf Corn Weed Grass Quarter        A + B  0.25 + 1.0 7BS 0 10D 10D 9RS 8RS 10D 2B 9RS 6SB 0 10D 4SR 7RS "      " 2.0 10D 0 10D 10D 9RS 8RS 5SB 3SB 9RS 7BS 0 9BS 3S 6RS " " 3.0 9BS 0      10D 10D 9RS 10D 10D 4S 10N 9BSR 0 9BS 4S 7S " " 4.0 10D 1S 10D 10D 9RS      8S 7SR 4S 10N 9BS 0 8BS 4S 7S " 0.5 + 1.0 9BS 0 10D 10D 8RSB 8S 7RS 3BS      8BS 8BS 0 8BS 5SB 8SB " " 2.0 10D 0 10D 10D 9BSR 8S 8SR 2SB 9RS 9BS 0      9BS 6SB 8SR " " 3.0 10D 0 10D 10D 9BSR 8SR 8SR 4S 9RS 9BS 0 9BS 5S 7S "      " 4.0 10D 0 10D 10D 10D 10N 10N 4S 9RS 9BS 2S 9BS 6SB 8S " 1.0 + 1.0 10D      0 10D 10D 10D 10N 10D 6BS 5SB 9BS 0 9BS 9BS 9RS " " 2.0 10D 2S 10D 10D      10D 9.5RS 10N 5BS 5SB 9BS 0 10D 9.5BS 8SR " " 3.0 10D 0 10D 10D 9BSR 9RS      9BSR 6BS 9RS 10D 1S 9BS 9.5BS 8S " " 4.0 10D 0 10D 10D 10D 1ON 10N 4SB      9RS 10D 0 9BS 9.5BS 9SR " 2.0 + 1.0 10D 3S 10D 10D 10D 10D 10D 9BS 7BS      10D 3S 9BS 9BS 9RS " " 10D 4S 10D 10D 10D 10D 9SR 8BS 9RS 10D 5SB 9BS      10D 9S " 2.0 + 3.0 10D 3S 10D 10D 10D 10N 10N 9BS 8RS 10D 4S 9BS 10D 9SR      " "  4.0 10D 1S 10D 10D 10D 10D 9.8BSR 9BS 10N 10D 3S 10D 10D 1ON      Control 0   0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE 2 XVI       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-1H- IMIDAZO(4,5-b)PE      PIDINE ("A") WITH PROPAZINE ("B")         Rates Morning    Velvet Lambs Jimson Barnyard  Large  Foxtail      Johnson Compounds Lbs./Acre Glory Pigweed Ragweed Sorghum Leaf Quarter      Weed Grass Rice Crabgrass Sorghum Millet Corn Grass        A + B 1/2 3/4 8DS 8SD 8BSD 0 3BSD 9RSD 9.5SD 5SD 2BS 3S 0 6BSD 0 8BSD      " 1/2 11/2 8.5BSD 8SD 9BSD 0 5BSD 9RSD 9BSD 4SD 3BS 4.5RS 0 7BSD 0 7BSD      " 1/2 3 8.5BSD 8.5SD 9BSD 0 3CS 8RSD 9.5BSD 8BSD 5BS 7.5RSD 0 6BSD 0      7.5BSD " 1 3/4 10D 8.5SD 9BSD 3BS 7.5BS 8RSD 9.5SD 7BSD 1BS 9RSD 0 9.5SD      2S 9.5BSD " 1 11/2 10D 8SD 9.5BS 3BS 10D 9RSD 9.5BSD 8.5BSD 2BS 8RSD 2BS      10D 0 9.5BSD " 1 3 10D 8.5SD 10D 2BS 10D 9RSD 9.5BSD 9.5BSD 4BS 9RSD 1BS      9SD 0 9.5BSD "  11/2 3/4 10D 8SD 8BSD 2BS 8BSD 9RSD 9.5SD 10D 6BSD      9.5RSD 2BS 10D 0 10D " 11/2 11/2 9.5BSD 8BSD 10D 2.5BS 9.5BS 9RSD 9.5BSD      9BSD 5BSD 10D 2BS 10D 2BS 9.5BSD " 11/2 3 10D 8BSD 10D 3BS 10D 9RSD 10D      9.5BSD 7BSD 8SD 3.5BS 10D 1S 9.5BSD " 2 3/410D 8BSD 9BSD 3BS 9.5BSD 9RSD      9.5BSD 9.5BSD 5BSD 9.5SD 4BS 10D 2S 10D " 2 11/2 10D 8BSD 9.5BSD 2BS 10D      9.5RSD 10D 10D 6.5BSD 10D 3BS 10D 1S 9BSD " 2 3 10D 8.5BSD 10D 2BS 9BSD      9.5RSD 9.5BSD 10D 6BSD 9RSD 2BS 10D 0 10D Control -- -- 0 0 0 0 0 0 0 0      0 0 0 0 0 0 Control -- -- 0 0 0 0 0 0 0 0 0 0 0 0 0 0 Control -- -- 0 0      0 0 0 0 0 0 0 0 0 0 0 0

    TABLE XVII       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)PY      RIDINE ("A") WITH SIMAZINE ("B")         Rates Morning    Velvet Lambs Jimson Barnyard  Large  Foxtail      Johnson Compounds Lbs./Acre Glory Pigweed Ragweed Corn Leaf Quarter Weed      Grass Rice Crabgrass Corn Millet Sorghum Grass        A + B 1/4 1/4 6.5BSD 8.5BS 6.5SD 0 2S 6.5S 9.5SD 0 1BS 6BS 0 4.5BS 0      4BS " 1/4 1/2 10D 7BSD 7RSD 0 5CS 10D 10D 6BSD 2BS 7.5BS 0 6BS 0 7BSD "      1/4 1 10D 8.5BSD 9SD 0 6CS 9SD 9.5SD 8BSD 2BS 9BSD 0 7BSD 0 9BSD " 1/4 2      10D 8.5BSD 9SD 0 8SD 9.5SD 10D 9.5BSD 3BS 9BSD 6BSD 9.5BSD 2S 9BSD " 1/2      1/4 10D 8BS 8BSD 0 5CS 9BSD 9SD 3BS 1B 6SD 0 7.5BSD 0 8.5BSD " 1/2 1/2      9.5BSD 8.5BS 9.5SD 0 6.5BSD 9BSD 9.5SD 3BS 6.5BS 8SD 0 8BSD 0 9BSD " 1/2      1 9.5BSD 9BS 9.5SD 0 6.5BSD 10D 10D 3.5BS 5BS 9SD 0 9.5BSD 0 8.5BSD "      1/2 2 10D 9.5BS 10D 0 7CSD 10D 10D 9.5BS 5BS 9.5SD 0 10D 4BS 9.5BSD " 1      1/4 9.5BSD 9BS 9SD 0 7SD 9BS 10D 7BSD 3BS 9BSD 0 9BSD 0 10D " 1 1/2 10D      6.5S 9SD 1S 6SD 9BS 9.5BSD 9.5BSD 2BS 9.5BSD 1.5S 9.5BSD 3BS 10D " 1 1      10D 8S 10D 0 7SD 7.5BS 9.5BSD 9.5BSD 6BS 10D 0 0.5BSD 3BS 10D " 1 2 10D      9.5BS 8SD 1S 9SD 10D 10D 9BSD 4BS 10D 1.5S 10D 5BS 10D " 2 1/4 10D 9BSD      9.5BSD 1.5S 10D 10D 10D 9BSD 6BSD 9.5BSD 0 10D BS 10D " 2 1/2 10D 9.5BSD      9.5BSD 2S 9.5BSD 9BS 9.5SD 9BSD 6BSD 9.5BSD 1.5S 10D 5BS 9.5BSD A + B 2      1 10D 9.5BSD 9.5BSD 1S 9BSD 9.5BS 10D 9.5BSD 6BSD 10D 1S 10D 4.5BS      9.5BSD " 2 2 9.5BSD 9BSD 9.5BSD 1.5S 9.5BSD 10D 10D 9.5BSD 6BSD 10D 1S      10D 6BS 9.5BSD Control -- -- 0 0 0 0 00 0 0 0 0 0 0 0 0

    TABLE XVIII       COMBINATION OF 1-METHOXY-6-(CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)P      YRIDINE ("A") WITH TRIFLURALIN ("B")         Rates  Morning  Foxtail  Barnyard Large    Velvet  Jimson Johnson      Lambs Compounds Lbs./Acre Glory Corn Millet Ragweed Grass Crabgrass      Pigweed Sorghum Rice Leaf Corn Weed Grass Quarter        A + B 0.21  0.25 6SB 0 8SR 5S 9RS 10N 10N 8SR 5SC 0 0 2S 5SR 4S " "      0.5 8SB 0 9SR 10D 9RS 9.5RS 10N 7SR 6SC 3SB 0 5SB 4S 5S " " 1.0 10D 0      9BSR 10D 9RSB 9.5RS 9.5BS 9SR 5SCB 8BS 2S 8BS 9.5RS 9BSR " " 2.0 10D 5S      10N 10D 9.5RS 9.5RS 10N 8SR 5SB 10D 4S 9BSR 10N 10N " 0.42  0.25 5SB 4S      9RSB 5SB 10N 10N 10N 10N 8SC 2S 4SC 2SC 9.5RS 6SR " " 0.5 6BS 5S 9.8RS      10D 9.5RS 9.5RS 10N 10N 9SC 3S 4S 5SB 10N 8SR " " 1.0 10D 4S 9.8RS 10D      10N 10N 10N 9.8RS 8SC 10D 5SB 9BS 9.5RS 9RS " " 2.0 10D 5S 10N 10D 10N      10N 10N 10N 8SCR 10D 5SC 9BS 9.5RS 10N " 0.83  0.25 6SB 7FSC 10N 7RS      9.5RS 10N 10N 10N 9CRS 3S 7CSF 3S 9.5RS 8RS " " 0.5 7BS 8RSF 10N 10D 10N      10N 10N 9.9RS 9CRS 4SB 8CSF 8BSF 9.8RS 9.5RS " " 1.0 8SB 9BSF 9.8RS 10D      9.8RS 10N 10N 10N 9SRF 7BS 7SC 9.5BS 9.9RS 9.5RS " " 2.0 9BS 8SCB 10N      10D 10N 10N 10N 10N 9SCR 9.8BS 7SCB 9BSF 10N 9.5RS " 2.0   0.25 7SB 9RSF      10N 8BSR 10N 10N 10N 10N 9.5SR 6S 9RSF 4SB 10N 10N " " 0.5 7SB 9RSB 10N      9.5BS 10N 10N 10N 10N 9.8RS 5SF 8FSB 6SF 10N 10N A + B 2.0  1.0 10D 9FSB      10N 10D 10N 10N 8SR 10N 9RS 10D 9SF 9.5BS 10N 9.5RS " " 2.0 10D 9FSB 10N      10D 10N 10N 9.5RS 10N 9.5SR 9.5BS 9FSB 10D 10N 10N Control  0  0 0 0  0      0 0 0 0 0 0 0 0 0

    TABLE XIX       COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)PY      RIDINE ("A") WITH TCA ("B")         Rates Morning    Velvet Lambs Jimson Barnyard  Large  Foxtail      Johnson Compounds Lbs./Acre Glory Pigweed Ragweed Corn Leaf Quarter Weed      Grass Rice Crabgrass Corn Millet Sorghum Grass        A + B 1/4 3/4 2CS -- -- 1S 0 0 2.5S 1S 0 1S 0 4BFD 0 3BS " 1/4 11/2      2CS -- -- 2S 0 2S 4S 0 5BS 8SD 0 7BFD 0 3BS " 1/4 3 2CS -- -- 1S 0 3RS      2S 2S 9BSD 9BSD 0 9BFD 0 4BS " 1/4 6 1C -- -- 1S 0 3S 3S 7BFS 10D 7BSD 0      9.5BFR 7BFD 8BSD " 1/2 3/4 3BS -- -- 0 0 2S 7BSD 3S 6BSD 5BS 0 8.5BSD 0      4BS " 1/2 1 1/2 5BS -- -- 0 4CS 3S 6BSD 4BS 5BS 3BS 0 7BSD 0 8BSD " 1/2      3 4BSD -- -- 0 5CBS 8RS 10D 8BSD 8BS 5SD 0 7BFSD 3BFS 9BSD " 1/2 6 7BSD      -- -- 3FS 6BSD 8RSD 9BSD 6BSD 8BSD 7BSD 2FS 9.5BSD 8BFSD9BSD " 1 3/4      9BSD -- -- 0 7BSD 7RS 9BSD 7BSD 3BS 6BSD 1S 8BSD 0 8BSD " 1 11/2  9BSD      -- -- 0 5BS 7RS 9.5BSD 9BSD 8.5BSD 9BSD 1.5S 9BSD 3BS 9BSD " 1 3 5CBS --      -- 0 6CBS 4RS 9BSD 6BSD 7BSD 9BSD 2S 10D 3BS 8BSD " 1 6 6BCSD -- -- 1S      8BSD 8RS 9BSD 9BSD 9BSD 9BSD 0 9.5BSD 6RFS 10D " 2 3/4 10D -- -- 2S 9BSD      7RS 9.5BSD 9.5BSD 6BSD 8BSD 1S 7BSD 3BS 9BSD " 2 11/2  10D -- -- 1S 9BSD      7RS 9.5BSD 9.5BSD 6BSD 9BSD 2S 10D 3BS 9.5BSD " 2 3 10D -- -- 3S 9BSD      8RS 9BSD 9.5BSD 7BSD 8BSD 0 10D 6BSD 9.5BSD " 2 6 10D -- -- 4FS 10D 9RS      9BSD 9.5BSD 9BSD 8.5BSD 3FS 10D 8.5BSD 10D Control -- -- 0 -- -- 0 0 0 0      0 0 0 0 0 0 0

EXAMPLES 104-107

Additional evaluations were conducted, in accordance with the procedures of the foregoing examples, with 1-methoxy-5-chloro-2-trifluoromethyl-1H-imidazo(4,5-b)pyridine and with 1-methoxy-2,6-bis(trifluoromethyl)-1H-imidazo(4,5-b)pyridine. Each was employed in combination with alachlor and separately in combination with atrazine. The results were as set forth in the following tables.

    TABLE XX       COMBINATION OF 1-METHOXY-5-CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)PY      RIDINE ("A") WITH ALACHLOR ("B")          Rates Morning  Foxtail  Barnyard Large    Velvet  Jimson Johnson      Lambs Compounds Lbs./Acre Glory Corn Millet Ragweed Grass Crabgrass      Pigweed Sorghum Rice Leaf Corn Weed Grass Quarter        A + B  0.25 + 0.5 3SE 2S 9.5BS 9.5RS 9.5RS 10D 9.5RS 9RSF 9RS 9.5BS 0      9BS 9RSB 10D " "  1.0 4SE 0 10D 10D 10D 10D 10D 9RSF 9.8RS 8BS 0 9.5BS      9RSB 10D " "  2.0 6BSC 2S 10N 10N 10D 10N 10N 9.5BS 10N 9BS 1S 10D 9.5BS      10N " "  4.0 9.5BS 0 10D 10D 10N 10N 10N 9.5BS 10N 9.5BS 3S 10D 10D 10D      " 0.5 + 0.5 9.5BS 2BS 10D 9RS 9RSB 9.5RS 10N 8SFB 9.5RS 10D 2S 10D 8RSB      9.5RS " "  1.0 9BS 0 10D 10D 9.5RS 10D 10N 9.5BS 10N 10D 0 10D 8BSR 9RS      " "  2.0 10D 2S 10D 10D 10D 10N 10N 9.8BS 10N 10D 2S 10D 9.5RSB 9.5BS "      "  4.0 10D 0 10N 10D 10N 10N 10N 10D 10N 10D 2S 10D 10D 10D" 1.0 + 0.5      10D 0 10D 10D 10D 10N 10D 9.8BS 9.5RS 10D 1S 10D 8RSB 10D " "  1.0 10D      2S 10D 10D 10N 10N 9.5RS 8BSF 10D 10D 0 10D 9.5BS 9.5RS " "  2.0 10D 1S      10D 10D 10N 10N 10N 9.8BS 10N 10D 2S 10D 9.5BS 10N " "  4.0 9.8BS 2SB      10N 10N 10N 10N 10N 9.8BS 10N 10D 2SB 10D 10D 10D " 2.0 + 0.5 10D 0 10D      10D 10D 10D 10D 9BSF 9RSB 10D 0 10D 9BSR 10D " "  1.0 10D 2S 10D 10D 10D      10N 10D 10D 8RSB 10D 0 10D 10D 10D " "  2.0 10D 3S 10N 10D 10N 10N 10N      10D 10N 10D 4SB 9BSR 9.5RS 10D " "  4.0 10D 3S 10D 10N 10N 10N 10N 10D      10N 10D 2S 10D 9.5BS 10N Control 0   0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE XXI       COMBINATION OF 1-METHOXY-5-CHLORO-2-TRIFLUOROMETHYL- 1H-IMIDAZO(4,5-b)PY      RIDINE ("A") WITH ATRAZINE ("B")         Rates Morning  Foxtail  Barnyard Large    Velvet  Jimson Johnson      Lambs Compounds Lbs./Acre Glory Corn Millet Ragweed Grass Crabgrass      Pigweed Sorghum Rice Leaf Corn Weed Grass Quarter        A + B  0.25 + 0.25 7BS 1S 7BS 10D 6SB 4SB 6SB 0 5B 8BS 0 10D 0 7SB " "       0.5 8BS 0 7BS 10D 5SB 3SB 7SB 0 5B 9BS 0 9BS 0 7SB " "  1.0 10D 0 8BS      10D 9BS 8BS 8BS 0 5B 10D 0 10D 2S 8BS " "  2.0 10D 0 9BS 10D 8BS 7BS 7BS      0 9B 10D 0 10D 2SB 9BS " 0.5 + 0.25 9BS 0 9BS 10D 7SB 8BS 8BS 0 8B 10D 0      10D 3SB 8BS " "  0.5 10D 0 10D 10D 7BS 5SB 8BS 1S 6B 7.5BS 0 10D 3SB 9BS      " "  1.0 10D 2C 9.5BS 10D 7BS 6BS 8BS 2S 5B 10D 3SC 9BS 3SC 10D " "  2.0      10D 0 9.5BS 10D 9BS 7BS 9BS 1S 9B 10D 0 10D 3S 9BS " 1.0 + 0.25 10D 1S      9.5BS 10D 9BS 6BS 9BS 2S 8B 10D 0 10D 3S 9BS " "  0.5 10D 2SB 10D 10D      9.5BS 7SB 8BS 3SB 9B 10D 0 10D 4SB 9BS " "  1.0 10D 1SB 10D 10D 9.5BS      9BS 9BS 3SB 10D 10D 0 10D 4SB 9BS " "  2.0 10D 3S 10D 10D 9BS 7BS 9BS      5SB 10D 10D 1S 10D 3SB 9BS " 2.0 + 0.25 10D 4SB 10D 10D 9.5BS 8BS 9BS      8BS 10D 10D 3SB 10D 9BS 9BS " " 0.5 10D 4SB 10D 10D 9.5BS 9.5BS 9.5BS      8BS 9.5BS 10D 3S 10D 5SB 9BS " "  1.0 10D 6SB 10D 10D 9BS 9.5BS 9.5BS      8BS 10D 10D 2S 10D 5SB 10D " "  2.0 10D 3S 10D 10D 10D 9.8BS 9.5BS 8SB      9B 10D 3S 10D 6SB 9BS Control 0   0 0 0 0 0 0 0 0 0 0 0 0 0 0

    TABLE XXII       COMBINATION OF 1-METHOXY-2,6-BIS(TRIFLUOROMETHYL)- 1H-IMIDAZO(4,5-b)PYRI      DINE ("A") WITH ALACHLOR ("B")  Rates Morning  Foxtail  Barnyard Large       Velvet  Jimson Johnson Lambs Compounds Lbs./Acre Glory Corn Millet      Ragweed Grass Crabgrass Pigweed Sorghum Rice Leaf Corn Weed Grass      Quarter  A + B  0.25 + 0.5 2E 0 9.5BS 4SB 9RS 7RSB 8BSR 1S 5RB 4SB 0 3SB 4      SR 9RS " "  1.0 3SFE 0 10D 6SB 9.5RS 10D 10D 5SF 8RS 5SB 0 5SB 7RS 9RS "      "  2.0 5SEF 0 10D 9.5BS 10N 10D 10N 5SF 9RS 5SB 0 6SB 9RS 9RSB " "  4.0      7SBF 3SF 10N 9.5RS 10D 10D 10D 7SFB 10N 8SB 2S 8BS 10D 10N " 0.5 + 0.5      5SBF 0 10D 5SB 9RS 8RSB 10D 3SB 7SRB 7BS 0 8BS 7RSF 8SR " "  1.0 6SBF 0      10D 7SR 9.5RS 10D 10D 3SF 9RSB 9.5BS 0 9BS 7RSB 9BSR " "  2.0 9.5BS 1S      10D 10N 10D 10N 10N 9BSF 9.5RS 9BS 1S 9RS 9.5BS 10N " "  4.0 9.5BS 3S      10D 10D 10D 10D 10D 9.5BS 10N 9BS 4SF 10D 9.5BS 10N " 1.0 + 0.5 9.5BS 0      10D 6S 7SR 8RSB 10D 4SFB 4S 9BS 0 9BS 8BS 9BS " "  1.0 8BS 0 10D 7BS 9RS      9RSB 10D 8BSF 9RS 9BS 0 9.5BS 9.5BS 9.5BS " "  2.0 9.5BS 4SB 10N 8RS 10D      10D 10N 8FSE 10N 9.5SF 3S 9.5BS 9.5BS 9.5BS " "  4.0 10N 0 10N 9SR 10N      10N 10D 9.5BS 10N 9BS 2S 9BS 10D 9.5RS " 2.0 + 0.5 10D 0 10D 8BS 9RS 8BS      9BSR 8BS 8RS 9.5RS 2S 9BS9BSR 9.5RS " "  1.0 10D 3S 10D 7S 9.5RSB 9.5BS      10D 8BS 9RS 9BS 1SB 9.5BS 9.5BS 9.5RS " "  2.0 10D 3S 10D 8SR 9.5BS 10D      10D 9BSF 9.5RS 9.5BS 4S 9.5BS 10D 10N " "  4.0 10D 3SB 10N 10D 10N 10N      10N 9BSF 9.5RS 9.5BS 3S 9.5BS 10D 10N Control 0   0 0 0 0 0 0 0 0 0 0 0      0 0 0

    TABLE XXIII       COMBINATION OF 1-METHOXY-2,6-BIS(TRIFLUOROMETHYL)- 1H-IMIDAZO(4,5-b)PYRI      DINE ("A") + ATRAZINE ("B")  Rates Morning  Foxtail  Barnyard Large      Velvet  Jimson Johnson Lambs Compounds Lbs./Acre Glory Corn Millet      Ragweed Grass Crabgrass Pigweed Sorghum Rice Leaf Corn Weed Grass      Quarter  A + B  0.25 +  0.25 3BS 0 5B 2S 0 2S 5SB 0 2B 2S 0 2B 0 7BS " "       0.5 5BS 0 4B 8BS 4S 4SB 6BS 0 3B 4SB 2S 8BS 0 8BS " "  1.0 10D 0 7BS      8BS 3SB 4SB 8BS 1B 7B 10D 0 9BS 1B 8BS " "  2.0 10D 0 9BS 10D 8BS 6BS      8BS 0 8B 10D 0 10D 2B 7BS " 0.5 +  0.25 9BS 0 3B 4BS 3SB 6BS 7SB 0 5B      4SB 2S 8BS 0 6SB " "  0.5 9BS 0 4B 6S 4S 4S 6SB 0 6B 5SB 0 10D 2S 7SB "      "  1.0 10D 0 5BS 10D 4SB 5SB 7BS 0 7B 9BS 0 10D 0 7SB " "  2.0 8BS 4SB      5BS 10D 7BS 7BS 8SB 0 5B 10D 0 9BS 2S 7BS " 1.0 +  0.25 9.5BS 0 7BS 4SB      4S 5SB 3SB 0 0 8BS 0 9BS 2S 8BS " "  0.5 10D 0 7BS 7SB 4S 5SB 8SB 1B 3BS      9.5BS 0 9BS 2S 8BS " "  1.0 9.5BS 0 7BS 8BS 5SB 5SB 8BS 1B 5B 10D 1S      9.5BS 1S 9SB " "  2.0 10D 0 9.5BS 9SB 8BS 8BS 8BS 3SB 8B 9.5BS 0 9.5BS      2SB 9BS " 2.0 +  0.25 9.5BS 0 8BS 8BS 5SB 8BS 8BS 4B 5B 9BS 0 9BS 3BS      8BS " "  0.5 10D 0 8BS 9BS 4B 6BS 8SB 3BS 5B 9BS 2S 9BS 4BS 9BS " "  1.0      10D 0 8BS 10D 5SB 7BS 8SB 2B 7B 10D 2S 10D 4SB 8BS " "  2.0 10D 0 8BS      10D 8BS 7BS 8SB 5B 7B 10D 3S 10D 4B 9BS Control 0   0 0 0 0 0 0 0 0 0 0      0 0 0 0

EXAMPLES 108-110

1-Methoxy-6-chloro-2-trifluoromethyl-1H-imidazo(4,5-b)-pyridine was evaluated separately in combination with each of alachlor, atrazine, and propachlor. The evaluations were conducted under field conditions at a location in the southern coastal plain. The compounds were formulated by tank-mixing a commercial application of the respective known herbicide with an emulsifiable concentrate of the 1-methoxy-6-chloro-2-trifluoromethyl-1H-imidazo(4,5-b)-pyridine. The tank-mixed formulation was then applied to the soil surface immediately after planting with corn. Prior to planting, the plots had been broadcast with foxtail millet (Setaria italica) and sicklepod (Cassia obtusifolia) and disced. However, additional weed seeds, including weed seeds of each of the named species, were present as a natural infestation of the plots. The growing conditions were typical for the area. Evaluations were made of corn injury and stand reduction, also of the control of the weed species. There were three replications per treatment pattern, and the ratings were averaged for the three replications. Results are given in the following table for stand reduction.

                                      TABLE XXIV                                   __________________________________________________________________________     COMBINATION OF 1-METHOXY-6-CHLORO-2-TRIFLUOROMETHYL-1H-IMIDAZO(4,5-b)PYRID     INE ("A")                                                                      WITH ALACHLOR ("B"), ATAZINE ("C"), AND PROPACHLOR ("D")                       __________________________________________________________________________                          Percent                                                                 Reduction in                                                                          Corn       Weed Control                                   Rate in       Emergence                                                                             Injury     Foxtail Millet Sicklepod                       Treatment                                                                            Lbs./Acre                                                                              (10 Days)                                                                             23 Days                                                                              64 Days                                                                             16 Days                                                                             24 Days                                                                             42 Days                                                                             16 Days                                                                             24 Days                                                                             42                    __________________________________________________________________________                                                              Days                  A " " " B A + B " " "                                                                1.0  1.5 2.0 3.0 2.0  0.75 + 0.75 0.75 + 1.0 1.0   + 1.0 1.0  +                        0 0 9 10  3 0 2 0 6                                                                   0 0 13  17  0 0  0 0 0                                                               3 0 17  23  0 0 0 0 0                                                               61 33 11 56 67 89 100  100                                                          88 92  100  100  62 83 96 96 100                                                    90  98 100 100  97  95  98 100                                                 100  14 14  0  0  0 14 14  0                                                             14  0  0  0  0  0 57                                                            71                                                                                  ##STR11##            "     1.5 + 2.0                                                                              0      0     0    100  100  100  29    0   NO                    C     2       4      0     7    11   33    88   0   57   READ-                 A + C 0.75 + 0.75                                                                            0      0     0    44   79    97   0   14   ING                   "     0.75 + 1                                                                               0      0     3    44   79    98   0   14   MADE                  " " " D A + D " " " "                                                                1 + 1 1 0 0 0 0 10  0 0  0  5 + 2  0.75 + 3  1 + 2 1 + 5 1 +                                  0 0 0 0 0 0 0 0 0                                                                    0 0 7  0 7 0 0 0 0                                                                  72 61 50 72 100  100  100  100                                                      96 96 100  100  92100  96 100                                                       100 100 100  95  97 100  100                                                        29 57 43 14  0 14 29 14                                                             43 86 86  0  0 29                                                                    ##STR12##            __________________________________________________________________________

the compounds of the present invention can also be employed as the starting materials in a reduction to prepare yet other compounds useful as herbicides. In general, this reaction comprises the treatment of one of the compounds of the present invention with a nucleophilic reagent; the reaction results in loss of the 1-OR³ moiety and introduction of the nucleophilic ion into the pyridine ring, or in reduction. Suitable nucleophilic reagents are compounds containing an amine group, in the case of those present compounds which are ethers; and compounds containing a halide ion, in the case of those of the present compounds which are esters, including the carbamate and sulfonate esters. The overall reaction scheme can be summarized as follows: ##STR13## Rearrangement is the course of reaction except where a bromide or iodide is employed, in which case, reduction occurs. The introduced nucleophilic moiety locates at either the 5 or 7 positions, depending on the identity of R² and the nucleophilic moiety.

In the instance of either reduction or introduction of the nucleophile, the products are useful, in accordance with prior teachings, as herbicides. Sec U.S. Pat. No. 3,459,759.

Two synthetic routes are useful in the preparation of the starting 1-hydroxy compounds: ##STR14## In a first synthetic route, the compounds are prepared by reduction of a precursor of the formula: ##STR15## The reaction is believed to go through several intermediates which are not isolatable, but yields as product the desired 1-hydroxy-1H-imidazo(4,5-b)pyridine compound. The reaction conditions are not critical; however, it is generally preferred to employ as reducing agent two moles of hydrogen per mole of the nitropyridineamine, in the presence of a minor amount of a catalyst comprising a noble metal, preferably palladium. In a representative synthesis, 1-hydroxy-6-chloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine was prepared as follows:

5-Chloro-3-nitro-2-(trifluoroacetamido)pyridine (2.0 grams) was hydrogenated with two moles of hydrogen in ethanol containing 0.5 gram of 5 percent palladium on carbon. The resulting reaction mixture was filtered and evaporated to separate the desired 6-chloro-1-hydroxy-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine compound which, after recrystallization from benzene melted at 268°-70° C.

Analysis, Calc.: C, 35.39; H, 1.27; N, 17.69.

Found: C, 35.59; H, 1.45; N, 17.77.

In a second synthetic route, a suitable 1-hyroxy compound ##STR16## is itself utilized as a precursor to other 1-hydroxy compounds which serve as starting materials for the preparation of the compounds of the present invention. In this route, the initially employed 1-hydroxy compound is subjected to reactions to introduce onto the pyridine ring one or more desired groups and/or to convert one or more substituents already present on the pyridine ring to the desired group or groups.

Thus, for example, the 1-hydroxy compound can be halogenated or nitrated at a position or positions previously unsubstituted. A nitro group already present can be reduced to an amino group; and an amino group already present can also be oxidized back to a nitro group. An amino group can also be diazotized and replaced by, for example, a halo group, a nitrile group, or a loweralkylthio group. Oxidation of the loweralkylthio-substituted compound yields the corresponding loweralkylsulfonyl-substituted compound. The fluorinated groups (R² --CF₃, --CF₂ Cl, or --CF₂ H) are readily obtained initially by conversion of a nitrile to a carboxyl group; subsequent treatment with SF₄ in the presence of HF yields the --CF₃ group. Alternately, conversion to an aldehyde and treatment with SF₄ alone yields the --CF₂ H group; and subsequent chlorination converts the --CF₂ H group to the corresponding --CF₂ Cl group. An alkyl substituent is introduced by reaction of an alkyl lithium with a halo-subststituted 1-hydroxy compound; and a perfluoroalkyl substituent is introduced by reaction of a halo-substituted 1-hydroxy compound with a perfluoroalkyl iodide in the presence of copper. These and numerous other conversion substitution reactions are well known to those skilled in the art. Attention is directed to Fieser and Fieser, Advanced Organic Chemistry (Reinhold Publishing Corp,, New York, N.Y., 1961), especially chapters 9 and 17. See also Wagner and Zook, Synthetic Organic Chemistry (John Wiley and Sons, Inc., New York, N.Y., 1953).

As will be understood by those skilled in the art, more than one of the foregoing reactions will be needed to complete the preparation of some of the compounds of the present invention; and in the case of all reactions, due considerations must be given to the orienting effect of substituent groups. Also, for those of the foregoing reactions which utilize a nucleophilic reagent, it may be necessary that the 1-hydroxy group first be converted to an ester of ether, as discussed hereinabove; and the reaction with nucleophilic reagent then conducted.

Preferred compounds of the present invention are those which are monosubstituted (n = 1) and the substituent (R²) is halogen, nitro, --CF₃, --CF₂ Cl, --CF₂ H, or loweralkylsulfonyl of C₁ -C₄.

A particularly preferred sub-genus of the compounds of the present invention is defined as follows: ##STR17## wherein R⁸ represents halo or --CF₃ ; R⁹ represents loweralkyl of C₁ -C₄, loweralkenyl of C₂ -C₄, benzyl, loweralkanoyl of C₂ -C₄, loweralkenoyl of C₃ -C₄, benzoyl, loweralkylsulfonyl of C1-C₄, or carbamoyl of the formula ##STR18## wherein X represents oxygen or sulfur, and one R⁴ represents phenyl, loweralkyl of C₁ -C₄, or loweralkenyl of C₂ -C₄, and the other R⁴ represents hydrogen, loweralkyl of C₁ -C₄, or loweralkenyl of C₂ -C₄, subject to the limitation that both R⁴ moieties taken together do not contain more than six carbon atoms, or both R⁴ moieties taken together represent straight-chain alkylene of C₂ -C₆, both inclusive; and R¹⁰ represents trifluoromethyl, pentafluoroethyl, or 1,1,2,2-tetrafluoroethyl.

Other preferred compounds of the present invention are those of the formula ##STR19## wherein each halogen, R¹, and R³ are as defined hereinabove, and q is 2 or 3. Yet more preferred compounds are those of the foregoing formula wherein the halogen is chlorine, bromine, or fluorine; and even more preferred are those wherein the halogen is chlorine. A particularly preferred sub-genus is defined as follows: ##STR20## wherein R⁹ and R¹⁰ are as defined above. Additional examples of the preferred compounds described in this paragraph follow.

1-Hydroxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-imidazo(4,5-b)pyridine (1.5 grams; 0.005 mole) was taken up in acetone (30 ml.). Anhydrous sodium carbonate (.5 gram) and methyl iodide (.1 ml.) were added, and the reaction mixture was stirred at room temperature and monitored by TLC. When the reaction was complete, the reaction mixture was filtered and evaporated. The residue was taken up in ether, washed with sodium bisulfite, warmed with magnesium sulfate and charcoal, filtered, and evaporated. An oil was obtained, 1.6 grams. NMR showed a trace of methyl iodide; the oil was therefore rewashed and dried, 1.2 grams of 1-methoxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo-(4,5-b) pyridine as a light brown oil.

Analysis, Calc. C, 33.99; H, 1.58; N, 13.21.

Found C, 34.24; H, 1.58; N, 13.05.

In like procedures, the following were prepared:

1-allyloxy-5.6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine, m.p., 49-50° C.

1-benzyloxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine, m.p., 145-146° C.

1-isopropoxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine, m.p., 120°-121° C.

1-methoxy-5,6-dichloro-2-(trifluoromethyl)-1H-imidazo-(4,5-b)pyridine, m.p., 92-93° C.

1-isopropoxy-5,6-dichloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine, m.p., 73°-74° C.

1-allyloxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine was evaluated in the procedures reported in Examples 62-70 and in the procedures reported in Examples 71-76. The results were as follows:

                  TABLE XXV                                                        ______________________________________                                         Injury Rating on Preemergent Treatment                                                                Soy- Crab- Pig- Fox- Velvet-                            Lbs./Acre                                                                              Corn   Cotton  bean grass weed tail leaf                               ______________________________________                                         8       0      --      --   4D    4D   4D   4D                                 4       0      0       1B   4D    4D   4D   4D                                 2       0      0       1C   4D    4D   2BS  4D                                 1       0      0        0    3BS   3BS 1BS   3BS                               ______________________________________                                    

                  TABLE XXVI                                                       ______________________________________                                         Injury Rating on Postemergent Treatment                                                          Crab-    Pig-  Fox-  Velvet-                                 Lbs./Acre Corn    grass    weed  tail  leaf                                    ______________________________________                                         8         4D      4D       4D    4D    4D                                      4         4D      4D       4D    4D    4D                                      2         4D      4D       4D    4D    4D                                      1         2B      3B       4D    3B    3B                                      ______________________________________                                          (letter symbols are used with the same meanings assigned in Examples           77-87.)                                                                  

The compounds which are the subject of the present application are suitable for use as rodenticidal agents. This use of the compounds is disclosed aand claimed in copending application Ser. No. 517,265, filed Oct. 23, 1974, and allowable as of Aug. 29, 1975. Application Ser. No. 517,265 is incorporated herein by reference thereto.

As disclosed in application Ser. No. 517,265, those compounds which bear a single substituent located at the 6-position are believed to be operative through a mechanism of anti-coagulation. The remainder of the compounds apparently do not share the anti-coagulant mechanism but the precise mechanism of these compounds is not understood.

Therefore, the preferred compounds which are of the formula ##STR21## are useful as rodenticidal agents, but are operative by a mechanism other than anti-coagulation. 

I claim:
 1. ##STR22## wherein R¹ represents hydrogen, chlorine, fluorine, difluoromethyl perfluoroalkyl of C₁ -C₆, or radical of the formula ##STR23## wherein each Z independently represents hydrogen or halogen and m represents 0 or 1; R³ represents alkyl of C₁ -C₈, alkenyl of C₂ -C₈, cycloalkyl of C₅ -C₆, benzyl, phenethyl, or tetrahydro-2-pyranyl; and q represents 2 or
 3. 2. A compound of claim 1 wherein both or all halogens are chlorine.
 3. A compound of claim 2 wherein R³ is loweralkyl of C₁ -C₄.
 4. The compound of claim 3 which is 1-methoxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine.
 5. The compound of claim 3 which is 1-methoxy-5,6-dichloro-2-(trifluoromethyl)-1H-imidazo(4,5-b)pyridine.
 6. The compound of claim 3 which is 1-methoxy-5,6-dichloro-2-(pentafluoroethyl)-1H-imidazo(4,5-b)pyridine.
 7. The compound of claim 3 which is 1-isopropoxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine.
 8. The compound of claim 2 which is 1-allyloxy-5,6-dichloro-2-(1,1,2,2-tetrafluoroethyl)-1H-imidazo(4,5-b)pyridine. 